TRAINING REPORT ON NETWORKING

SWAMI PARMANAND COLLEGE OF ENGINEERING & TECHNOLOGY SIX MONTHS INDUSTRIAL TRAINING REPORT ON

NETWORKING (MCSE & CCNA) AT

JETKING

ACKNOWLEDGEMENT I feel deeply indedted to Mr. XYZ, Microsoft trainer who delivered valuable lesson on MCSE, his indepth knowledge about the subject helped me understand the subject in better way. His method of teaching the minute details helped me a lot to acquire the insight into the subject.

I am also grateful to Mr. XYZ, CCNA trainer for giving best knowledge about CCNA.the way he instilled knowledge of the subject was undoubtly praise worthy and valuable.

I am also thankful to Jetking institution as a whole that is doing yeoman’s service by teaching the learner avreast with the computer , networking and hardware knowledge that is the need of the day.

I will be failing in my duty if I do not acknowledge my husband Mr. XYZ who always stood by my side during my studies. I am indepted to my son’s XYZ who never clamed my time and get bore by my long absence rather silent.

Last but not the least, I thank all my classmates at Jetking for extending kind co-operation.

XYZ

List of Figures Figure No.

Name of Figure

Page No.

1

Computer network

6

2

Local Area Nework

9

3

LAN Classification

9

4

Campus Area Network

10

5

Metropolitan Area Network

11

6

To find location of a computer using FQDN

24

7

Tree structure

25

8

Structure of domain forest and domain tree

36

9

Multi-Master Mode

37

10

Parent child relationship model

40

11

Direct Sharing Scenario

43

12

ICS scenario

44

13

Scenario of win proxy server

45

14

NAT Server

46

15

VPN server

48

16

LAN routing

52

17

Static routing

53

18

Architecture of router

60

19

Variable Subnet Mask

75

20

Scenario of Telnet

76

21

Scenario of Static Routing

81

22

Routing table

86

23

Routing table of covered networks

86

24

Routing loops

87

25

OSPF Scenario

99

26

VLAN Operation

105

27

VTP Configuration

110

28

VTP Pruning

111

29

IEEE 802.11 Standard

114

List of tables Table No.

Name of table

Page No.

1

Difference between Workgroup & Domain

7

2

Comparison between IPv4 and IPv6

12

3

Address Classes

13

4

Category and Speed of UTP cables

17

5

Colour Coding for straight Cable

18

6

Colour Coding for Crossover cable

19

7

Colour Coding for Rollover Cable

20

8

Operating Systems

21

9

Difference between Workgroup and Domain

34

10

Exchange Server with different operating systems

56

11

Router interfaces and connectors

62

12

Router Ports

63

13

Default address mask in binary & dotted decimals

71

14

Decimal and Binary values of subnet mask

72

15

Subnet mask, valid hosts, broadcast address

74

16

Routing table

86

17

Difference between RIPV1 & RIPV2

90

18

Difference between IGRP and RIP

91

CONTENTS Sr. No.

Topic

1

INTRODUCTION Company Profile LITERATURE RIEVIEW NETWORKING

1.1 2 3 3.1

6

3.1.1 Models of Networking

6

3.1.2 Categories of network

8 12

3.2.2 MAC Addressing

15

NETWORKING MEDIA Ethernet Cabling

3.4 OPERATING SYSTEM 3.4.1 Types of Operating Systems DNS SERVER 3.5.1

PARTS OF DNS SYSTEM

3.5.2 DNS Zone 3.6 DHCP SERVER

3.7

12

3.2.1 IPAddressClasses

3.3.1

3.5

1 1 5 6

Introduction to networking

3.2 IP ADDRESSES and MAC Addresses

3.3

Page No.

15 17 20 20 22 23 26 28

3.6.1 Working of DHCP Server

29

3.6.2 InstallationStepsofDHCPServer

31

ACTIVE DIRECTORY

33

3.7.1ActiveDirectoryServices

34

3.7.2

40

CHILD DOMAIN

3.8

INTERNET SHAREING

42

3.8.1 Direct Sharing

42

3.8.2 ICS (Internet Connection Sharing)

43

3.8.3 Win Proxy Server

45

3.8.4 NAT (Network Address Translation)

45

3.9 VIRTUAL PRIVATE NETWORK (VPN)

47

3.9.1

VPN components

48

3.9.2

Types of VPN

49

3.10 ROUTING 3.10.1

51 Types of Routing

3.11 EXCHANGE SERVER

51 56

3.11.1 Elements of Exchange Server

56

3.11.2

Exchange Version

56

3.11.3

Requirements for Exchange Server

57

3.12 Open System Interconnection (OSI) Model 3.12.1 Description of Different Layers 3.13 ROUTERS

57 58 60

3.13.1 Router Architecture and its Key Component

60

3.13.2 Router Interfaces & Ports 62

3.14

3.13.3 Modes of Router

63

3.13.4 Configuring Password

65

3.13.5 Managing Configuration

66

SUBNETTING 3.14.1

Advantages of subnetting

70 70

3.14.2 Types of Subnetting 3.15 TELNET

73 75

3.15.1 To Access the Device Remotely

75

3.15.2 Commands to assign IP addresses to the interfaces 76 3.16 ROUTING

79

3.16.1 TYPES OF ROUTING

79

3.16.2 Routing Protocol Basics

84

3.1.3 R IP (Routing Information Protocol)

88

3.1.4

91

IGRP ( Interior Gateway Protocol)

3.1.5 EIGRP(Enhanced Interior Routing Protocol)

93

3.1.6 OSPF (Open Shortest Path First)

95

3.17 LAN SWITCHING

100

3.17.1 SWITCH

3.18

100

3.17.1.1

VLAN (Virtual LAN)

103

3.17.1.2

Vlan Trunking Protocol (VTP)

108

Wi-Fi (WIRELESS FIDELITY)

113

3.18.1 Wireless LAN

113

3.18.2 Wireless Standards

114

3.18.3

115

Wireless Security

4

CONCLUSION

117

5

REFRENCES

118

1. INTRODUCTION This project report pertains to six months industrial training that I had underwent at JETKING, Chandigarh as part of curriculum of degree in Bachelor of technology in Electronics and Communication engineering as required by Swami Parmanand College of engineering and technology (affiliated to Punjab Technical University, Jalandhar) .

I learnt a lot from professional managers and skilled engineers. I had a great learning experience as trainee in this firm. I learnt a lot about how different networks are controlled in the industry or any department with the help of networking processes, under MCSE and CCNA. I have learnt about different type of servers like DHCP Server, DNS Server, NAT Server. Also I have learnt how to control the LAN and MAN networks under MCSE (Microsoft Certified System Engineers) and how to control MAN and WAN networks under CCNA (CISCO Certified System Engineers).

Justification cannot be done to whatever I have learnt in these six months within a few pages but I have still tried my best to cover as much as possible in this report. In this report I have tried to sum up the technical knowledge I have gained in my six months of training.

1.1

Company Profile Jetking is an organization came into establishment in1947. Jetking is India’s

number one Computer Hardware and Networking Institute.

Birth and Evolution It took a lot of failure before mankind tasted technological success. Jetking evolved in

tune with the changing face of technology. During 55 years in the field of electronic technology. Jetking successfully trained thousands of students to overcome failure for high paying careers.

1947

Birth

1962

Pioneered “Do-It-Yourself Kits” in India

1972

Introduced Asia- 72, Fairchild and Wildcat transistors

1986

Became a Public Limited Company and also introduced entertainment electronics product-T.V sets, Two-in-ones and amplifiers.

1990

Launched Jetking School of Electronics Technology

1993

Network of Jetking training centers spread all over India

1994

Opening of Jetking, Chandigarh

1995

Tie-up with Heath kit Educational System (U.S.A.)

1996

Introduced advanced courses on Pentium, Notebooks, Modems, Email/Internet, LAN 4.X

1997

Novell Education Academic Partner

1998

Representative for International Correspondence School (ICS), USA in India

1999

Added cyber technology to the curriculum

2003

ISO 9001-2000 company and Authorized Microsoft online testing centre (VUE) for MS, CISCO, MCSA, MCSE, CCNA, A+ etc.

Mr. Suresh G. Bharwani is the CHAIRMAN and MANAGING Director of Jetking Infotrain Ltd. India’s leading Computer Hardware and Networking Institute. With the vision to promote and the conviction to deliver the widespread propagation of computer hardware and networking education across the nation, Mr. Bharwani was the first to set up an training institute offering innovative courses in computer hardware in 1990.

Jetking’s core competency lies in providing complete training and developing hardware engineers and professionals with sound technical knowledge. It focuses on the overall development of personality of an individual with emphasis on personality development, presentation and communication skills, leadership skills etc.

Jetking has established more than 125 operational centers and 250 faculties across the country and has trained over 3,50,000 students who have move onto the crave success- full career. With its alumni placed in the best of organizations in India and some abroad, Jetking,s vocational training and placement promises has helped build the career prospects of many young boys and girls.

The company has been awarded the ISO 9000:2000 certification in 2003.The company has been awarded the “ Maharashtra IT Award” for a key role in manpower activities in year 2006-07,it was felicitated with Franchise Award as Best Franchisor for the year 2007-08.Also,ranked 4th in the list of 26th hot franchises as per outlook money magazine.

Mr. Suresh Bharwani was awarded with “Pike’s Peak Award” by the Bob Pike Group USA for effective implementing smart lab plus for making technical training fun, faster and easier for non- technical person.

Across all the sectors, industries are upgrading their information technology system. Industries ranging from plastics, chemicals, textiles and power to the automotive and telecom sector are now IT savy. Government and public sectors are going hi-tech with EDI and computer networks. The IT industry, software companies, data centers, ITenabled services providers are all equipped with advance IT system and networks. The increasing number of call centers, BPO’s etc., have given a further boost to the hardware and networking industry.

The courses in jetking comprises lecture and theory session, with a great focus on active participation through smart lab plus ,that focuses on audio visual and learning with hands-on training and equips students with an in depth domain knowledge that is technical; it also equips students with soft skills ,to face the multi-faceted challenges of corporate world.

PLACEMENT: Jetking is the first and only institute that promises the 100% jobs guarantee to its students. The companies that have recruited jetkings students include:

Samsung, Sun Micro system, IBM, Canon, Siement, reliance, TATA, Compaq HP invent, IT-T solutions, Videsh Sanchar Nigam Limited, D-Link, Novell, Dell, Wipro, LG, ICIC Infotech and several other MNCs. Any student who has qualified his or her HSC/SSC examination is eligible to take up a course at jetking. The one year program Jetking certified hardware and networking professionals give 680 hours of in-depth knowledge to a student in Basic electronics and computer applications. Computer hardware and peripherals, window 2003 administrator and network administrator (soon it will be replaced with window server 2008).Apart frame technical knowledge there are personality development sessions which groom the student’s personality, their ability to perform better.

Jetking, India’s leading hardware and networking training institute has trained over 3,00,000 students from its 125 centers spread across India. With its alumni placed in the best of organizations in India and some abroad, Jetking vocational training and placement promises has helped build the career prospects of many young boys and girls.

Jetking has partnered with some of the worlds most renowed names in networking to provide you with cutting edge courses and technologies. With academic partnerships with Microsoft, Comp TIA,LINUX, NOVELL, and person VUE .

Jetking Chandigarh is a division of Hi-Tech point. Hi-Tech point is an ISO 90012000 IT company. It was established in year 1993 and run by a company of IT professionals. Jetking Chandigarh branch is considered to be the best centre among all centers. It has bagged number 1 center award consecutively for last 7 years. Here training on various fields is going on like Basic Electronic, Hardware, Networking, JCHNP Analog and Digital electronics and Hardware, RHCE, RHCSS, MNA, MCSE (Microsoft System Engineers), MCITP, MNA, CCNA (CISCO Certified Network Associate), CCNP(CISCO Certified Network Professional).

Partnership with industry leaders like Microsoft and Red Hat Jetking ensure its students authentic courseware and technology.

2.

LITERATURE RIEVIEW

Computer Networking is a very vast project in the present developing era of electronics and communication. Now a days, computers are used in a wider range. All the organizations are using multiple computers within their departments to perform their day to day work. Computer network allows the user to share data , share folders and files with other users connected in a network. Computer Networking has bound the world in a very small area with it wide networking processes like LAN, MAN, WAN. The courses in jetking comprises lecture and theory session, with a great focus on active participation through smart lab plus ,that focuses on audio visual and learning with hands-on training and equips students with an in depth domain knowledge that is technical; it also equips students with soft skills ,to face the multi-faceted challenges of corporate world.

3. NETWORKING 3.1

Introduction to networking Networking is a practice of linking of two or more computing devices such as

PCs, printers, faxes etc., with each other Connection between two devices is through physical media or logical media to share information, data and resources. Networks are made with the hardware and software.

Cable/media

Fig 1: computer network

3.1.1 Models of Networking Model means the connectivity of two computers. We have many types of networking models. (i)

Client – Server Model

(i)

(ii)

Peer to Peer Model (Workgroup Model)

(iii)

Domain Model

Client –Server Model In a Client server model we have one server and many clients. A Client can share

the resources of server, but a server cannot share the resources on clients.

On the point of view of administrator it’s very easy to control the network because we combine with the server also at security point of view. It is very useful because it uses user level security in which users have to remember only one password to share the resources. (ii) Peer to Peer Model (Workgroup Model) In Peer to Peer networking model all computers are in equal status, that is we cannot manage centralization, administration secutity. In Peer to Perr networking client use operating system like Window 98, Window XP, Window 2000, Window Vista. (iii) Domain Model It is a mixture of client server and peer-to-peer model. In this clients can share their resources as peer-to-peer but with the permission of the server as in client server model therefore it is commonly used model because in this security is more as we can put restriction on both server and clients.

Difference between Workgroup & Domain Table 1 Workgroup

Domain

1. It is a peer to peer networking model.

1. It is a server based networking model.

2. There is no client and no server. All the 2. There is a centralized dedicated server computers are in equal status.

computer called domain controller which controls all other computers called clients.

3. This model is recommended for small 3. This model is recommended for large networks, upto 10 computers.

networks.

4. There is no centralized administrated 4. There is centralized administration and separately.

each PC can be administrated and managed from the server.

5. In this model, low grade OS like 5. in this model high grade OS like WIN 2000/XP professional, WIN 98 etc. can be 2000/2003 Server can be used. used.

6. Users accounts are created in each PC 6. Users accounts are created on the server and are called as Local Users.

side and are called Domain Users.

3.1.2 Categories of network Networks can be categorized as per geographical area to be covered by the network. Computer network are divided into four categories includes: Local Area Network (LAN), Campus Area Network (CAN), Metropolitan Area Network (MAN) and Wide Area Network (WAN).

3.1.2.1

Local Area Network (LAN) LAN is a computer network that is used to connect computers and work station to share data and resources such as printers or faxes. LAN is restricted to a small area such as home, office or college. Devices used in LAN are : HUB and switch.

Media for LAN is UTP cables. Figure 1.2 shows how all work stations, server and printer are interconnected with the help of the network device.

Fig 2: Local Area Network Types of LAN In LANs, data can be transferred using techniques like token passing. As per techniques used for data sharing, LANS are classified into Ethernet, Token Bus, Token Ring and Fiber Distributed Data Interface (FDDI).Figure 3.3 shows LAN classification.

Fig 3: LAN classification

Advantages of LAN a). Provides communication in smaller networks, easy to install and configure. b). many users can share data or network elements at the same time which results in fast work.

Disadvantages of LAN a). limited number of computers are connected in a LAN. b). LAN cannot cover large area. c). Network performance degrades as the number of users exceeds.

3.1.2.2 Campus Area Network (CAN) Campus Area Network is a computer network made up of two or more LANs within a limited area. It can cover many buildings in an area. The main feature of CAN is that all of the computers which are connected together have some relationship to each other e.g. different buildings in a campus can be connected using different CAN. It will help to interconnect academic departments, library and computer laboratories. CAN is larger than LAN but smaller than WAN. Figure 3.4 shows a CAN network.

Fig 4: Campus Area Network

Devices used in CAN are : HUB, Switch, Layer-3 switch, Access Point .And the media used for CAN is Unshielded twisted pair of cables and Fiber Optics Cable.

3.1.2.3

Metropolitan Area Network (MAN)

MAN is the interconnection of networks in a city. MAN is not owned by a single organization. It act as a high speed network to allow sharing resources with in a city. MAN can also be formed by connecting remote LANs through telephone lines or radio links. MAN supports data and voice transmission. The best example of MAN is cable T.V network in a city.

Fig 5 : Metropolitan Area Network

3.1.2.4

Wide Area Network (WAN) WAN covers a wide geographical area which include multiple computers or

LANs. It connects computer networks through public networks like, telephone system, microwave, satellite link or leased line.

Most of the WANs use leased lines for internet access as they provide faster data transfer.

WAN helps an organization to establish network between all its departments and offices located in the same or different cities. It also enables communication between the organization and rest world.

Devices used in WAN is only Router

3.2 IP ADDRESSES and MAC Addresses It is also called as logical addresses. IP is a 32 bit long and it is divided into 4 octets and dot (.) is used to separate one octet from another. It is represented in the form of decimals. There are two versions of IP addresses: -

IPv4

-

IPv6 Table 2

Comparison between IPv4 and IPv6

IPv4

IPv6

-

It is 32 bit long.

-

It is 128 bit long.

-

It is divided into 4 octets.

-

It is divided into 16 octets.

-

Ipv4 performs broadcasting,

-

IPv6

-

doesn’t it

support

multicasting and unicasting.

broadcasting,

performs

IPv4 is divided into 5 classes:

multicasting and unicasting.

A to E.

-

Ipv6 doesn’t support classes.

IPv4 is in decimal form.

-

IPv6 is in hexadecimal form.

3.2.1 IP Address Classes IP address is a 32 bit address. It is divided into various classes namely Class A, Class B, Class C, Class D and Class E. TCP/IP defines Class D for experimental purpose.

TCP /IP address contains two addresses embedded within one IP address; Network address and host address as shown in figure 3.1

NETWORK

HOST ADDRESS

ADDRESS 0 bits

31 bits

Class A consists of 8-bit network ID and 24-bit host ID. Class B consists of 16bit network ID and 16-bit of host ID. And Class C consists of 24-bit of network ID and 8-bit of host ID. Address Classes Table 3: Address Classes Addres

Starting

Range of First Mask Value

s

Bits

Octet

Class

(first-byte)

Class A 0

1to 127

255.0.0.0

Valid Hosts

256*256*256-2= 16,777,214

Class B

10

128 to 191

255.255.0.0

Class C

110

192 to 223

255.255.255.0 256-2

Class D 1110

224 to 239

Reserved for multicasting

Class E

240 to 255

Reserved

1111

development `

256*256-2=65,534

for

research

and

3.2.1.1 How to Assign IP Address to Computer An IP address assigned to a computer may either be permanent address or address that is assigned to a computer on a time lease or for temporary basis. Hence, the address granted to computers is divided into two categories Dynamic IP addresses and Static addresses.

Dynamic IP Addresses Dynamic IP addresses are assigned to the devices that require temporary connectivity to the network or non-permanent devices such as portable computer. The most common protocol used for assigning Dynamic IP address is DHCP also called

Dynamic Host Configuration Protocol. The DHCP grants IP address to the computer on lease basis.

Static IP Addresses Static IP addresses are assigned to the device on the network whose existence in the network remains for a longer duration. These static IP addresses are semi-permanent IP addresses which remain allocated to a specific device for longer time e.g. Server.

3.2.1.2 How to Configure IP Address in window 2003 •

Right click on My Network Places- properties

•

right click on working LAN card- properties

•

select internet protocol (TCP/IP) -properties

•

Tick on- Use the following IP addresses - now fill the IP address e.g 10.0.0.1

•

Tick on –Use the following DNS server address

•

Fill the preferred DNS server – 10.0.0.1

•

Ok

•

Close

Now check the connectivity of computer with itself with command Start-run-cmd-ping 10.0.0.1

3.2.2 MAC Addressing MAC address is a hardware address that is embedded in the NIC card. It is also known as hardware address or physical address. Every NIC card has a unique MAC address assigned by IEEE. MAC address is used to identify the nodes at lower levels of OSI model. The MAC address operates at the data link layer of the OSI model.

MAC address is a 12 digit hexadecimal number (48 bit address). It is made up of numbers from 0-9 or a letter from A-F. MAC address can be written in any one of the formats: ►

MM:MM:MM:SS:SS:SS

►

MM:MM:MM:SS:SS:SS

T o identify the MAC address in window: •

Click Start →Run

•

Enter cmd in the Open text book

•

Type ipconfig /all

•

Press Enter

The 12 digit MAC address will be shown as say 00:11:11:EA:8D:F6

3.3

NETWORKING MEDIA

To do networking we need to use some type of media. There are many types of media. (i)

Coaxial Cable

(ii)

Fiber optic cable

(iii)

Twisted Pair of Cables

(iv)

Micro- wave

(iv)

Satellite

Coaxial Cable Coaxial cable consists of an insulated copper conductor surrounded by a tube shaped copper braid outer copper tune and the inner conductor have the same axis of curvature hence it called coaxial cable. It is basically of two types: (i)

Base Band Cable (RG – 59)

(ii)

Broad Band Cable (RG – 58)

We used Base Band signal cable in Networking of Computers, It is so called because it carries single frequency. Its speed is 10 Mbps and impedance is 50 Ω. Where as Broad Band Cables carries multiple frequencies. Connector used for Coaxial cable is

BNC(British Novel Connector) connector. ARCnet uses RG-62 coaxial cable. It has an impedance of 93 Ω and has a comparatively lesser attenuation, hence yield greater distances. These cables are expensive and provide high propagation factor.

Fiber Optical Cable Fiber optic cable consists of a very fine fiber made from two types of glass, one for the inner core and the other for the outer layer. Here signal is transmitted in the form of light.

Different varieties of fiber optics is used depending on the size of the network. Single mode fiber optics is used for networks spanning longer distance. Fiber Optics has lower propagation factor than coaxial cable. It is a costly but more secure transmission media.

Twisted Pair Cable There are two wires, which are twisted with each other to avoid EMI (Electro Magnetic Induction).these cables are easy to terminate. However they have a slightly higher value of attenuation value and hence have limited distance covering capacity.

Connector used for Twisted Pair of Cable is (Registered Jack) RJ-45 and RJ-11. There are two types of twisted pair of cables: •

STP (Shielded Twisted Pair): In this an extra wire which is called shielded wire is wrapped over the inner

cover which holds copper in pairs. This protection is used to protect signal from external noise.

•

UTP (Unshielded Twisted Pair) In this type of wire no shielded cover is there for extra protection from noise.

There are different categories of UTP cables:

Categories of UTP Cables Table 4: Category and Speed of UTP cables

Category

CAT-1

Speed

56 Kbps 4 Mbps

CAT-2 CAT-3 CAT-4 CAT-5

10 Mbps 16-20 Mbps 100 Mbps

CAT-6 CAT-7

3.3.1

Ethernet Cabling

There are three types of Ethernet cables: •

Straight cable

•

Crossover cable

•

Rolled cable

3.3.1.1 Straight cable It is used when we have to connect •

PC TO Switch

•

PC to Hub

•

Hub to Router

•

Switch to Router

Colour Coding for straight Cable TABLE 5

1Gbps 1Gbps

568A

568B

(one end)

(other end)

(one end)

Green/white

Green/white

Orange/white

Orange/white

Green

Green

Orange

Orange

Orange/white

Orange/white

Green/white

Green/white

Blue

Blue

Blue

Blue

Blue/white

Blue/white

Blue/white

Blue/white

Orange

Orange

Green

Green

Brown/white

Brown/white

Brown/white

Brown/white

Brown

Brown

Brown

Brown

3.3.1.2 Crossover Cable It is used when we have to connect: •

PC to PC

•

Hub to Hub

•

Switch to switch

•

Router to Router

•

PC to Router

•

Hub to Switch

Colour Coding for Crossover cable Table 6 Colour Coding for Crossover cable

(one end)

(other end)

(other end)

Orange/white

Green/white

Orange

Green

Green/white

Orange/white

Blue

Blue

Blue/white

Blue/white

Green

Green

Brown/white

Brown/white

Brown

Brown

3.3.1.3 Rollover Cable Rollover cable isn’t used to connect any Ethernet connections together, but Rollover cable can be used to connect a host to a router console serial communication (com) port.

NOTE: Straight cable and Cross cables are used for data transfer but Rollover cables are not used for data transfer.

There are two methods for manufacturing Rollover cables:

Table 7 Colour Coding for Rollover Cable

568A (one end)

568B (other end)

(one end)

(other end)

Green/white

Brown

Orange/white

Brown

Green

Brown/white

Orange

Brown/white

Orange/white

Orange

Green/white

Green

Blue

Blue/white

Blue

Blue/white

Blue/white

Blue

Blue/white

Blue

Orange

Orange/white

Green

Green/white

Brown/white

Green

Brown/white

Orange

Brown

Green/white

Brown

Orange/white

3.4 OPERATING SYSTEM 3.4.1 Types of Operating Systems (i) DOS (Desktop Operating System)

(ii) NOS (Network Operating System)

Table 8: Operating Systems DOS

NOS

1. It is a desktop operating system.

1. It is a network operating system.

2. It is used in small networks.

2. It is used for large networks.

3. In this OS, there is less security.

3. In this OS, there is more security.

4. In this OS, all computers are clients.

4. In this OS, there are servers and

5. In this OS, MS-DOS, GUI package clients.

Win 3.1, Win 95, Win 98, Win ME comes.

5. In this OS Win NT, Win 2000, Win 2003, LINUX, UNIX, Novell and MAC comes.

3.4.1.1 Introduction to Window 2003 Server

Window server 2003 (also referred to as WIN 2k3) is a server operating system produced

by Microsoft. Introduced in 24th April 2003 as the successor to window 2000 server, it is considered by Microsoft to be the corner stone of its window server system line of business server products. An update version Window Server 2003 R2 was released manufacturing on 6th dec, 2005. its successor window 2008 was released on 4 th feb, 2008.

According to Microsoft, window server 2003 is more scalable and deliver better performance than its predecessor window 2000.

Features of Window 2003 (i)

A significant improved version of Internet Information Service (IIS)

(ii)

Increased default security over previous version due to the built in firewall and having most services disabled by default.

(iii)

Manage your server-a role management administrative tools that allow an administrator to choose what functionality the server should provide.

(iv)

Improvement to Active Directory.

(v)

Improvement to Group Policy handling and Administration.

(vi)

Provides a Backup system to restore lost files.

(vii)

Improved disk management, including the ability to Backup from shadows of files, allowing the Backup of open files.

(viii)

Improved security and command line tools which are part of Microsoft initiative to bring a complete command shell to the next version of window.

(ix)

Support for a hard based “Watch Dog Timer”, which can restart the server if the operating system does not suspend with in a certain amount of time.

Removed Features •

The ability of creating server disk automated system recovery (ASR) is used instead .

Edition of Window 2003 Window server 2003 comes in a number of editions, each targeted towards a particular size and type of business. In general, all variant of window server 2003

have the ability to share files and printers, act as application server and host message queue, provide email services, authenticate users, act as an X.509 certificate server, provide LDAP (Light Weight Directory Access Protocol) services, serve streaming media, and to perform other server-oriented functions.

3.5

DNS SERVER DNS stands for domain name system. DNS system is a standard technology

for managing the names of websites and other internet domains. DNS techniques allows you to type names into your web browser like computer networking, about computer and allow your computer to automatically find that address on internet. DNS is the resolution mechanism used by Window Server 2003 clients to find other computers and services running on those computers for computers in a window 2003 network infrastructure to talk to one another, one of the key ingredients is the DNS server .Host name alone do not communicate globally but communicate locally, but if domain name is added along with it then the host name can communicate globally. DNS is use for name reservation i.e. to convert IP address to host name and host name to IP address or the function of DNS is to resolve host name such as www.yahoo.com to an IP address. User identify only user friendly name and all computers and technologies identify IP address and MAC address DNS is use to solve this problem because DNS is used to convert host name FQDN (fully qualified domain name) to IP address and IP address to host name .

3.5.1 PARTS OF DNS SYSTEM (i)

Host name

(ii)

Domain name

(iii)

FQDN

(iv)

Namespace

(v)

DNS server

3.5.1.1 HOST NAME Host name is a computer name and is also called is NetBIOS (network basic Input/ output system) name. NetBIOS is actually an application layer protocol that can use the transport services of TCP/ IP when used in routed network. A NetBIOS name is 16- byte addresses that identify a NetBIOS resource on the network.

3.5.1.2 DOMAIN NAME Domain name is used to identifies the internet site one can identifies the location without having to remember the IP address of every location e.g. yahoo.com or gmail.com

3.5.1.3 FQD FQDN means fully qualified domain name which represents a hostname appended to the parent name space in hierarchy. Also in fully qualified domain name different levels of namespace are visualize as in fig below this hierarchy is visualized─ the root level namespace, top─ level domain, and so on, in use throughout the internet today. Left most portion of the FQDN is the host portion of the name. A host name is alias we give to an IP address.

Fig 6:To find location of a computer using FQDN FQDN is a unique name in the computer on the network. We can identify host id and location of a computer as in fig above. Suppose we want to find location of pc1 with IP address 20.0.0.1, which is in lab2, 2nd floor in the organization center. The FQDN for this is Pc1.row3.lab2.floor2.center.com But this address is very lengthy to locate pc1 so to simplify this we use “c name” technique as: Pc1.center.com=20.0.0.1 3.5.1.4 Domain Namespace DNS operates in what is known as DNS namespace. The DNS namespace is an organized, hierarchical division of DNS names. Domain namespace enable users to easily locate the network services and resources. The domain namespace include the root domain, the top level domain of the organization and organize these domain in a hierarchical tree structure. Namespace works on the hierarchical tree structure of root domain. There are total 13 root domain working in the internet, they are A, B, C, D, E, F, G, H, I, J, K, L and M. There is one root domain, which acts as the starting point of the

fully qualified domain names. This root domain is designated with a dot (.). Fig 6.2 shows the tree structure or domain namespace.

Fig 7: Tree structure or Domain Namespace 3.5.1.5 DNS server Any computer providing domain namespace is a DNS server. DNS server is used to convert host name FQDN into IP address and IP address into host name FQDN. To store the name-to-IP-addresses mappings so crucial to network communication, name server uses zone files.

3.5.2 DNS Zone Zone is the part of DNS database that contain record of domain or multiple domain.

If the domains represents logical division of the DNS namespace, zones represents the physical separation of the DNS namespace. In other words information about records of the resources within DNS domain is stored in a zone files, and this zone files exist on hard drive of server. Zone files are divided into one of two basic types:

3.5.2.1

•

Forward lookup zone: Provides host-name-to-IP-address resolution

•

Reverse lookup zone: Provides IP-address-to-host-name resolution

Resource record stored in a zone file

Each record stored in a zone file has a specific purpose. Some of the records set the behavior of the name server, others have the job of resolving a host name or service into an IP table. (i)

NS (Name Server): These specify the name servers that are authoritative for a given portion

of DNS namespace. These records are essential when DNS servers are performing iterative queries to perform name resolution. (ii)

SOA (Start of Authority): This resource record indicates the name of origin for the zone contains the name

of the server that is the primary source for information about the zone. The information in an SOA record affect how often transfer of the zone are done between servers authoritative for the zone. It is also used to store other properties such as version information and timings that affect zone renewal or expiration. (iii)

CNAME (Canonical Name):

CNAME can be used to assign multiple names of a single IP address.

For example, the server hosting the site www.abc.com is probably not named www, but a

CNAME record exist resolution of www to an IP address all the same. The CNAME record actually points not to an IP address, but to an existing A record in the zone.

3.5.2.2 Steps to Install and configure DNS server •

Start → control panel→ add and remove program

•

Add remove window components

•

Select networking services and click on detail button

•

Check box of DNS server

•

Ok and finish

3.5.2.3 Creating a Forward Lookup Zone •

Statically fill the IP address

•

Start →administrator tools

•

DNS→ right click on forward lookup zone

•

New zone→ next

•

Select primary zone→ next

•

Enter zone name (abc.com)→ next

•

Tick Allow both secure and non secure updates and secure dynamic updated

•

next→ next

•

now click on created zone (abc.com)

•

new host→ enter host name for global level (i.e by entering www) fill IP address of the web server , click on add button

•

enter another host name, a blank host with same IP i.e do not fill its host name

steps to change SOA and NS records •

Right click on SOA records → properties

•

Fill primary server e.g (www.abc.com)→ responsible person

•

host master.abc.com→ apply→ ok

•

right click on NS records

•

click on add button→ enter FQDN→ www.abc.com

•

resolve→ ok→ apply→ ok

Now go to start menu →

ping abc.com

On Client Side → To access DNS server fill IP address of server then use ping command e.g

ping www.abc.com

3.5.2.3

Creating a Reverse Lookup Zone

•

Right click on reverse lookup zone

•

New zone→ next→ select primary zone→ next

•

fill →Network ID→ next→ next

•

Select allow both non secure and non secure dynamic updates

•

Finish

•

Right click on created reverse zone→ new pointer

•

enter host IP number e.g (50.0.0.50)

•

enter FQDN (www.chd.com)

3.5.2.4 Some DNS Commands

(i) c:>tracert www.yahoo.com command is used to check the path , a data packet follow from one router to another router. (ii) c:>nslookup command display the domain name with IP (works only when reverse lookup zone is set up). (iv)

c:>ipconfig /all This command display FQDN, IP address, MAC address.

(iv) c:>ipconfig /flushdns This command flush or clear all the information in the cache that is retrieved from DNS server. (v) c:>ipconfig /displaydns

Display the current contents or entries in the cache. (vi)

c:>ip config /register register any DNS name

3.6 DHCP SERVER DHCP (Dynamic Host Configuration Protocol) is a protocol that allocates IP address to computer on a network. DHCP centralized the management of IP address allocation and reduces human error associated with manual IP configuration. DHCP server supplies all the necessary networking param-eters. Two things are always handed out as a part of DHCP configuration: IP address and subnet mask. Further DHCP will frequently configure clients with optional values, such as a default gateway, DNS server address, and the address of a Window Internet Naming Server, if one is present. Scenario showing DHCP server IP address allocation.

3.6.1 Working of DHCP Server (i)

DHCP Scope

(ii)

DHCP Super Scope

(iii)

Exclusion IP Range

(iv)

DHCP Lease Time

(v)

IP Reservation

DHCP Scope Scope having the range of IP address for providing dynamic IP address to other computer. A group of IP address within a scope is called as DHCP scope.

DHCP Super Scope A super scope is used to combine two or more scopes each serving different subnets, and can make the administration of several scopes on window 2003 DHCP server more manageable. Using super scope you can group multiple scopes as a single administrative entity that allows the client to lease from either one. With this feature, a DHCP server can:

•

Support DHCP clients on a single physical network segment where multiple logical IP networks are used. When more than one logical IP network is used on each physical subnet or network, such configuration is called multinets.

•

Support DHCP clients located on the far side of DHCP and BOOTP relay agent.

•

In multinet configuration, DHCP superscope can be used to group and activate individual scope ranges of IP addresses used on your network. In this way , a DHCP server computer can activate and provide leases from more than one scope to clients on a single physical network.

Exclusion IP range If you want to reserve some IP for any computer i.e if we want that from the series of 192.168.0.2 to 192.168.0.100 if we want that a series of IP addresses must not be assigned automatically then at can be done using exclusive IP range.

DHCP Leased Time DHCP lease time is validity of IP address. By default DHCP lease time is 8 days minimum,1 day maximum 999 days, 23 hours to53 day.

With in 8 days:After 80% of day clients demand new IP some times server refuse the client request.

After 87.5% of days it will retry, and if the server did not give the new IP address then the client will receive APIPA address (Automatic Private IP Address).

When a DHCP client is unable to locate a DHCP server, the client picks out a random IP address from the private APIPA address range of 169.254.*.*, with a subnet mask of 255.255.0.0. The 169.254.*.* IP range is private because that network number is not in use on the internet, it is random because the client generates an arbitrary host number for that network.

The significance of APIPA is that DHCP client computers that cannot find a DHCP server can still be assigned an IP address and communicate with other computers on the same subnet mask that also cannot find DHCP server. It allows communication when DHCP server is down or just plain not there. Note that APIPA does not assign a

default gateway, and therefore it cannot communicate with any computer that lives on the other side of a router.

IP Reservation There are some DHCP clients that you want to be the DHCP clients, but you will also want to make sure that they get same IP address every time. This can be done by statically filling the IP address. We can reserve IP address with the help of MAC address for a particular computer.

3.6.2 Installation Steps of DHCP Server •

start→ control panel

•

add and remove program→ add and remove window components

•

select networking services and click on detail button

•

check box of DHCP server

•

ok→ finish

3.6.2.1

Steps To Configure DHCP Server

•

start→ program→ administrative tool

•

select DHCP

•

create new scope in action menu→ new scope → next

•

give scope name→ next

•

give IP address range→ next

•

add exclusion name→ next

•

check lease duration→ next→ finish After DHCP server is configured, it is required to be authorized and DHCP scope

should be active. For that select DHCP server and click on authorize in action menu.

Then right click on scope name and click on active.

3.6.2.2

On Client Side

•

Go to LAN card properties → select TCP/IP protocol→ properties

•

Select obtain IP address automatically

•

Go to command prompt (cmd)

•

Give command

3.6.2.3

Backup of DHCP Server

We can take backup of all the configuration in DHCP server with the help of administrator. Backup means to export the DHCP database to another system, as it is helpful in case due to any reason our data is corrupted or deleted, we can take our database from the place where it is stored. Steps of taking backup : •

Stop the DHCP server and disable the DHCP server services

•

Copy the DHCP server directory to a temporary location, say pen drive or on a new DHCP server.

3.6.3 DHCP Relay Agent The DHCP relay agent is a software that listen DHCP discover packet and forward to DHCP server. In window 2003 server system the DHCP relay agent can be enabled as a part of Routing and Remote Access (RRAS).

3.6.3.1 Steps To Configure DHCP Relay Agent •

Set the network, fill the IP address and select two LAN cards

•

Open Routing and Remote Access → enable Routing and Remote Access

•

Right click on general new routing protocols

•

Select DHCP relay agent

•

New interface

•

Select LAN card which is to be connected to the cross cable i.e L1

•

Ok

•

Right click on relay agent → properties

•

Enter IP address of DHCP server

•

add→ apply→ ok

3.7

ACTIVE DIRECTORY

With the release of Windows 2000, Microsoft introduced Active Directory, a scalable, robust directory service. Active Directory is used to create server based networking.

Active Directory’s job is to store and make available a Directory database i.e information about the user, its class, name, address, mails, phone numbers, location.

Active Directory is a technology created by Microsoft that provides a variety of network services like Directory Services, DNS based naming and other network information. Active Directory also allows administrator to assign policies, deploy software and apply critical updates to an organizations. Active Directory was previewed in 1999, released first with window 2000 server edition and revised to extend functionally and improve administration in Window 2003. Additional improvements were made in Window server 2003 and Window server 2008.

The fundamental building block of Microsoft’s Directory services continues to be a domain. A domain is logically grouping of network resources, including shares, printers, groups and users accounts. The user account represents the individual to domain, and allows for different type of access and different types of tasks. Every users account is unique. It has uniqueness of the user account that allows administrator to control access for every member of domain.

There are two types of users accounts: local account and domain account. Local accounts are maintained in the local database of a computer and cannot be used to grant access to network resources. Local users are primarily used to administer a computer or to allow several people to share a single computer that is not a member of a domain.

Whereas domain users accounts are much more widely used in organizations that local user accounts because they allow for central administration and user can log onto any computer in the domain. Domain users accounts are stored in Active Directory.

3.7.1 Active Directory Services

A computer network can be divided logically into two networking models.

•

Workgroup

•

Domain

Difference Between Workgroup and Domain Table 9 Workgroup

Domain

1. It is a peer-to-peer networking 1. It is a server based networking model. model.

2.there is a centralized dedicated server 2. There is no client and no server. computer All computers are in equal status.

called

domain

controller

(DC)which controls all other computers called clients.

3.This model is recommended for small networks (upto 10 pcs).

3. This model is recommended for large networks.

4. There is no centralized Administration

and

each

PC

is 4. There is centralized administration

administrated separately.

and each PC can be administrated and managed from the server.

5.In this model, low grade operating system like 2000/xp professional, 5.In this model high grade operating win 98 etc can be used.

system ,like win2000/2003 server are used.

6. Workgroup can be given names like sales, HR, accounts etc.

6. Domain can also given names like abc.com, xyz.com etc.

7 Users accounts are created in each

PC and are called as “Local Users”.

7.Users accounts are created on sever side DC and are called as ”Domain Users”.

Active Directory uses domain to hold objects, each domain has security boundary.

Users must authenticates to the domain in which their users account resides before they can access resources, such as a shared folders. Active Directory also links related domains in a hierarchical structure and users can access resources in any of the domain in which their user account resides. The hierarchical structures of related domain is called a tree, and all domains in the tree share the same Domain Name System (DNS) namespace.

All the domains and the trees in a single organization are called a forest. All domains in the forest share same schema.

3.7.1.1

Types of Domain

•

Domain Forest

•

Domain Tree

•

Organization unit

Domain Forest A forest is created when window 2k3 server computer is configured as a domain controller. A forest is a collection of multiple domain link together and relationship between the domains.

Domain Tree A domain tree is made up when there is a parent child relationship between the domain in the forest. The child domain includes the complete parent domain name. a tree is a set of two or more domains sharing common namespace e.g we can create a parent domain and then child domain like mail.yahoo.com; where mail- child domain, yahoo- parent domain.

Fig 8: Structure of domain forest and domain tree Organization Unit (OU) Organization unit is the smallest unit in a domain network that can contain users, computer groups, shared folders, printers and group policy object in simple words. OU means department like sale department, accounts department like sales, accounts in a company OU can be used to apply different security policies to computer and users in different department. OU also helps in dividing administration among different administrator of managing only computer and users of sales department.

3.7.1.2

Types of Domain Controller (i)

PDC : Primary domain controller

(ii)

ADC : Additional domain controller

(iii)

BDC : Backup domain controller

Primary Domain Controller (PDC) This is the first domain controller, in this domain all entries are created in it like users account, group policy, Organization unit etc. All FSMO role are done in PDC.

Additional Domain Controller (ADC) It is a domain network, it is important to have more than one DC so that if one DC fails, the other DC will continue serving the client. There is also load balancing of Active Directory Service if we have more than one DC. The first DC we create is simply called PDC and if we create an extra DC then that DC is known as ADC. ADC has same configuration of AD as primary domain controller.

All domain controllers in a domain networking are masters. We can make a change in the active directory of any domain controller and that change is replicated to all other domain controllers. Replication takes place among all the domain controllers and it is controlled automatically. If we create a user in the first domain controller, it is automatically created in the ADC because of replication.

All the domain controllers in the domain networking are peers and this model is called as multi- master model .

Fig 9: Multi-Master Model

3.7.1.3 Requirements of Active Directory (i)

Window 2000/2003 server computer.

(ii)

Atleast one NTFS partition.

(iii)

Static IP address

(iv)

Atleast 1GB free hard disk space

(v)

LAN card enabled and connected to the network

(vi)

Install DNS, if not installed of Active Directory and configure it.

It should be noted that active directory cannot work without DNS.DNS is automatically installed and configured during the Active Directory installation.

3.7.1.4 Installation of Active Directory First of all fill the static IP address, then install DNS service into it and after that install the Active Directory •

start→ run→ dcpromo

•

Ok

•

Welcome to active directory → next→ next

•

Select domain controller for a new domain e.g (gmail.com)

•

Next

•

Domain NETBIOS name (gmail.com)

•

Next

•

Data folder, folder new tech directory service→ next (SYS VOL)

•

Next

•

Click on install and configure the DNS server on this computer to use this DNS server as its preferred DNS server.

•

Tick on permission compatible only with window server

•

Next

•

Enter the restore mode and the password

•

next→ next→ finish

•

now restart computer

Command used for the removal of Active Directory start→ run→ dcpromo

This command is also used to remove active directory, if after this command the active directory is not removed then type •

start→run

•

cmd→dcpromo /forceremoval

•

Ok

How to identify Active Directory installation •

Start → administrator tool After that if three options specified if come, it means that Active Directory

has been installed ─ Active Directory domain and trusts ─ Active Directory sites and services ─ Active Directory users and computer Open DNS console by •

Administrator tools→DNS

•

Forward lookup zone ─ msdcs.exam.edu ─ start of authority (SOA) ─ name server (NS)

Now ping active directory with domain name like •

start→ run→ ping gmail.com

Backup of Active Director Active Directory backup come in use when there is some problem in active directory. If there is any problem in active directory then remove it and restore the backup.

•

Start→ run→ntbackup→ok

•

Select advance mode and untick that is already ticked

•

Select backup

•

Selsct system state

•

Change backup path browse keep in your hardware and then send it to the pen drive

•

D:\adbackup

3.7.2 CHILD DOMAIN A domain is created say “xyz.com”. this domain is known as parent domain or the root domain. Now “chd.xyz.com” will be the child domain or the sub domain of xyz.com.

Fig 10 : parent-child relationship model A child domain is created to ease administration in a very large domain network. We can create the parent domain in the head office of the company and the child domain in the branch offices.

Each branch office will have its own administrator to manage the users of the child domain present in the branch office.

A true relationship is automatically created between the parent domain and the child domain. This means users in the child domain can access the file server of the parent domain. Moreover users of either domain can use clients of either domain for

logging in the domain but a user can always logon only in the domain in which his account resides, though he physically can use client pc of parent or client domain. Users of either domain can logon its own domain from either side but only when it use its own domain name. users of parent domain can communicate with child domain but he has to use its domain name for that.

3.7.2.1

Steps to create child domain

First of all install the active directory on pc1 i.e on the parent domain. Now make Tom user on it. On pc2 create the child domain, then make users on it, user- Ram Below are the steps to cerate child domain.

•

Fill the IP address in the child domain

•

Now ping to the parent domain with the domain name (xyz.com)

•

Run →dcpromo→ ok

•

next→ select domain controller for a new domain

•

next→ select child domain and existing domain name (mcse.com)

•

next

•

enter username, password and domain name

•

enter user parent domain name also enter child domain name

•

enter complete DNS name i.e xyz.mcse.com

•

next→ next→ next→ next

it should be noted that parent domain can logon into child domain but on the other hand child domain cannot logon to the parent domain. Also parent domain can apply policies or security on the child domain.

Make the client member by entering particular user with its domain name.

•

First right click on My Computer

•

Properties

•

Computer name

•

Change

•

Write domain name →ok Now logoff start and then write user name - Tom Domain name - mcse.com

Again logoff and check the other user Start-user name- abc Domain name – mail.mcse.com

3.8

INTERNET SHAREING We can share a single internet connection to multiple computers with the help of

networking or internet sharing. There are four ways to share internet. (i)

Direct sharing

(ii)

ICS – Internet connection sharing

(iii)

Win Proxy

(iv)

NAT – Network Address Translation

3.8.1 Direct Sharing Internet sharing can be done between computers directly, just by taking internet connection directly from ISP (Internet Server provider), then it is provided to ADSL model, ADSL modem is connected to the ISP through RJ-11 connector. Then it is connected to the switch with RJ-45 connector. Switch, further connects computers those have to be provided with internet connection. The scenario for direct sharing is as shown in figure:

Fig: 11: Direct Sharing Scenario ADSL modem has IP address 192.168.1.1. All the PCs are assigned with a DNS (Domain Name Server) and GW (gateway) -192.168.1.1. Also DHCP (Dynamic Host Communication Protocol) is enabled which will provide IP addresses to the PCs automatically.

3.8.2 ICS (Internet Connection Sharing) Internet Connection sharing provides an alternate way to provide Internet Sharing.

ICS requires a server with two network interfaces, one for the private internal network configured with IP 192.168.0.1 address and an adapter for public connection. ICS requires two connections in order to work: one public and one private i.e. ICS server requires two LAN cards, Internal (Private) and External (Public). Internal LAN card uses Local LAN card (L2) and External LAN card (L1) is used by Internet. ICS is designed to be as simple as possible. ICS works on following windows: XP, Vista, 2K3 Server, 2k3

Server SP1.it doesn’t work on the server in which AD+SP1 is present. The scenario for ICS is shown below:

Fig 12: ICS scenario Note:- When we configure ICS then the local card detect 192.168.0.1 address automatically.

How to configure ICS •

Open network and sharing center

•

Network- Properties

•

Click on Manage network connections

•

Right click on LAN Card which is used for internet- Properties

•

Click on sharing

•

Enable ICS

•

Ok

•

yes

3.8.3 Win Proxy Server

Win Proxy is a third party software which is used for sharing internet and we can also block the web site with the help of win proxy. WIN Proxy supports all the three classes A, B, C also it is supported by all operating systems. The scenario for WIN proxy is shown below:

Fig 13: scenario of win proxy server In win proxy as shown in the scenario above we can share internet. First of all a ADSL modem is connected to the ISP (Internet Service Provider) by a RJ-11 connector and other end of ADSL modem is connected to the PC1 through RJ-45. Assign IP address 192.168.1.1 to the ADSL modem also enable the DHCP server and set the start IP address of 192.168.1.2 and end IP address of 192.168.1.254. Then after ADSL modem connect PC1, assign GW 192.168.1.1 and

3.8.4 NAT (Network Address Translation) If we have to connect many computers with a single IP address then we will use NAT. NAT exchange IP packet between local network and internet. The routing and remote access server of window 2K3 server provide us with a component known as NAT. By enabling NAT on a Server 2003 system, you allow connected users on a private system to share a single connection to access a public network such as the internet i.e. NAT enable multiple client computer to connect the internet through a single publicly registered IP

address. A NAT server translate private IP address to public addresses. NAT eliminates the need for large number of IP addresses by mapping externally assigned IP addresses.

Fig 14: NAT server When deploying NAT, it is needed to configure setting on both the client side and the server side. On the server side of NAT fill the IP address statically.

3.8.4.1 Steps to enable NAT server

.

•

Open internet → Tools→ Internet options

•

connections→ LAN settings

•

untick the IP and port address

•

ok→ ok→ give site name

On the client side of NAT, client side is configured to obtain IP addresses

automatically and then restart the client system. Assuming NAT is used for address assignment, the client system will receive TCP/IP information from the NAT server. The client information includes: •

IP address from 192.168.0.0 private addressing range

•

Subnet mask (255.255.255.0)

•

DNS server address, which would be the address of the NAT interface on the server.

With the client side configured, there are few things to do on NAT server: The first step to configure NAT server is to actually install the Routing and Remote Access Services. To do this, start the Routing and Remote Access Service Setup Wizard.

•

Start→ administrator tools→ Routing & Remote Access

•

Right click on My Computer→ right click on computer name

•

Select option Configure and enable routing & remote access

•

Welcome to routing → next→ next

•

Select NAT→ next

•

Select LAN card which is to be connected to internet

•

next→ next

From any of the four methods of internet sharing only method is used at a time to remove the other method •

go to start→ setting

•

add & remove

•

change/ remove, tick on remove.

3.9 VIRTUAL PRIVATE NETWORK (VPN) A virtual private network is used to convert public network address to private network. All the clients of VPN dial to public IP address of VPN server and receive private IP from virtual VPN dynamic host protocol (DHCP).in VPN one can have multiple virtual connections to a single IP address. This way ,one network card can host several inbound connections, rather than require a modem and telephone line for each simultaneous remote user.

Fig 15 : scenario of VPN server Using VPN server we can connect many private networks to internet services i.e the remote connection. We can create a private network through public network, we can use firewall for security and data encryption in VPN server.

3.9.1 VPN components (i)

VPN server

(ii)

VPN Clients

(iii)

WAN Option

(iv)

Security Options

VPN Server VPN server, serve as the end points of a VPN connection. When configuring a VPN server, you can allow access to just that server, or pass traffic through VPN server so that the remote user gain access the resources of the entire network.

VPN Client VPN clients establish connection to VPN server. They can also be routers that obtain the router-to-router secure connection. VPN client software is included in all the modern window operating systems, including Window 2003 server. Router-to router VPN connection can be made from computers running server2003 and Windows 2000

running Routing and Remote Access. Additionally, any client that support PPTP or L2TP connections can be VPN clients of a window server 2003 system.

WAN Options These provide the physical mechanism for passing data back and forth. These connections typically include such similar network technologies such as T1or frame relay. In order for VPN connections to be successful, the VPN client and VPN server must be connected to each other using either permanent WAN connection or by dialing into an internet server provider (ISP).

Security Options Since a VPN uses a network that is generally open to the public, it is important that the data passed over the connection remain secure. To aid with secure communication routing and remote access supports such security measure as logon and domain security, data encryption, smart cards, IP packet filtering and caller ID.

3.9.2 Types of VPN (i)

PPTP (Point to Point Tunneling Protocol )

(ii)

L2TP (Layer 2 Tunneling Protocol) according to CCNA.

Point to Point Tunneling Protocol (PPTP) PPTP is Microsoft’s legacy protocol for supporting VPN. It was developed in conjunction with other communications companies such as Robotics as an extension to the PPP protocol. PPTP encapsulates IP or IPX packets inside of PPP datagram’s. This means that you can remotely run programs that are dependent upon particular network protocols. One of the keys to remember about PPTP is that the protocol provides encryption capabilities, making it much safer to send information over nonsecure networks.

Layer Two Tunneling Protocol (L2TP) L2TP is a standard based encapsulation protocol with roughly the same functionality as a Point-to-Point Tunneling Protocol (PPTP). One of the key differences

between Window’s server 2003 implementation of L2TPand it cousin PPTP is that L2TPis designed to run natively over IP networks only. This implementation of L2TP does not support native tunneling over X.25, frame relay, or ATM networks. Like PPTP, L2TPencapsulates Point-to-Point Protocol (PPP) frames, which then encapsulate IP or IPX protocols, allowing users to remotely run programs that are dependent on specific network protocols . But unlike the PPTP protocol, L2TP does not provide encryption of the data. For data security L2TPrelies on the services of another standards- based protocol, IPSec.

3.9.3

How to configure VPN

•

start→administrative tools

•

Routing and Remote access

•

Right click on computer name configure and enable Routing and Remote access

•

next→ select remote access (dial up or VPN)

•

next→ VPN→ next

•

select LAN card which is connected to internet (172.15.15.50) public IP

•

disable enable security → next

•

from a specific range of address→ next→new

•

enter the required range

•

ok→next→ no radius

•

next→ finish

3.9.4

Create users in VPN server

•

open user properties→ dial in → allow access

•

apply→ ok

3.9.5

Working on Client Side

•

Right click on My Network Places→ properties

•

Double click on New Network Wizard→ next

•

Connect to network at my work place→ next

•

Virtual private network connection→ next

•

Enter company name (abc)→ next

•

Enter public IP address of VPN server→ next

•

Any one use →next

•

finish

3.10

ROUTING It is a process of transferring information through an inter network i.e from one

network to another. Routing connect different networks having ID help in process of routing. The dial-in properties also allow for specific IP address to be assigned to a user.

This is the only way in Window Server 2003 that you can assign a specific IP to a user.

To assign a specific IP to a user, check the box next to assign A Static IP Address and enter a valid IP in the space provided. Static routing can also be specified as per user. By defining static routes, users can be limited to only specific parts of networks.

In an internetwork a router must then about all the networks present in the for effort websites, there are hardware routers like CISCO. Even win 2003 server computer configured as router. In simple words Router is a computer with two network cards.

These two network cards, then, are attached to two different logical IP networks. The routing table helps direct traffic that is passed through the router.

Now when there is a router, also there is a routing table, there is a need to configure the router in order for that router to pass along traffic to the proper network.

There are two ways the routing table can be built and modified: either manually or automatically.

3.10.1 Types of Routing (i)

Static Routing

(ii)

Dynamic Routing

3.10.1.1 Static Routing

In this routing information required for routing is manually entered into the router by administrator.

How to configure LAN routing •

Enter the static IP in the router

•

Administrator tools

•

Routing and Remote access

•

Right click on computer name (pcc1)

•

Configure and enable routing and remote access

•

next→ custom configuration

•

select LAN routing→next→ finish

•

yes and logon to see IP table route

Enable LAN routing Interface WAN IP 172.15.0.0 SNM 255.255.0.0 GW 20.0.0.2

enable LAN routing Interface WAN 10.0.0.0 IP 10.0.0.0 SNM 255.0.0.0 GW 20.0.0.1 Fig 16 : scenario for LAN routing

How to configure static routing At Router R1:

•

enable LAN routing

•

right click on static route

•

interface WAN

•

destination 172.15.0.0

•

mask 255.255.0.0

•

GW 20.0.0.2

At Router R2: •

Enable LAN routing

•

Right click on static route

•

Interface WAN

•

Destination 10.0.0.0

•

Mask 255.0.0.0

•

GW 20.0.0.1

Fig 17 : static routing

3.10.1.2 Dynamic Routing

The other way to manage a router routing tables is to let the computer do it for you. Just like DHCP allocate IP addresses, configuring the dynamic routing protocol usually means less errors due to human error, and less administrative overhead.

In dynamic routing, routing information is automatically entered in the router using protocols like RIP AND OSPF. These routing protocols used by Window Server 2003 use one of two kinds of algorithms to determine the best possible path for a packet to get to its destination, either distance vector or link state. RIP is used for small networks where as OSPF is used for large networks.

Routing Information Protocol (RIP) The distance vector protocol in use on Window 2003 is called Routing Information Protocol (RIP) for IP. This protocol was designed for the exchange of the routing information within a small to medium size IP network.

When Router is enabled on Window 2003 machine, the routing table includes entries only for the networks that are physically connected. When RIP is enabled for an interface, the router will periodically send an announcement of its routing table to inform other RIP routers of the networks it can reach. RIP version1 uses broadcast packets for its announcement. RIP version2 offers an improvement and can be configured to use either multicast or broadcast packets when communicating with other routers. Also, RIP version2 offers more flexibility in subnetted and classless inter domain routing (CIDR) environments.

The biggest advantage of RIPis its simplicity. With a few clicks in the Routing and Remote Access Server and MMC console, you can deploy RIP. With the RIP dynamic routing protocol installed on Window’s Server 2003, you get the following features: (i)

RIP version1 and version2, with the ability to configure individual network cards with separate versions.

(ii)

Calculations used to avoid routing loops and speed recovery of the network whenever topology changes occur.

(iii)

Route filters; you can configure RIP to except information from only certain networks, and also choose which routes will be shared with RIP routers.

(iv)

Peer filters, which allow control over which router announcements are accepted.

(v)

Simple password authentication support.

But there are significant drawbacks, which makes RIP a poor, if not unusable solution for large networks. For example, the maximum hop count used for RIP routers is15, making network 16 hops away (or more) unreachable where RIP is concerned.

Open Shortest Path First (OSPF) Where RIP is built to work to work in smaller networks, the Open Shortest Path First (OSPF) routing protocol is designed for large or very large networks. The goal is the same: information about connection to other networks is shared from one router to another. It offers several advantages over RIP, especially significant in large networks: (i)

Routes calculated with OSPF are always loop free.

(ii)

OSPF can scale much more easily than RIP.

(iii)

Reconfiguration for network topology changes is faster.

The biggest reason OSPF is the choice in large networks is its efficiency; instead of changing routing table via broadcast the way RIP does, OSPF configured routers maintain a map of the network. The mapping is called the link state database, OSPF routers keep the link state database up to date. Once changes have been made to link state database, an OSPF router’s link state database is recalculated.

As the networks start to multiply, the size of the link state database increases, and a corresponding hit on router performance results. To combat this, OSPF sub divide the network into smaller sections, called areas. Areas are connected to each other through a backbone area, with each router only responsible for the link state database for those areas connected to the routers. Area Border Routers (ABRs) then connect one backbone area to another.

The biggest drawback of OSPF is its complexity; OSPF requires proper planning and is more difficult to configure and administer.

3.11 EXCHANGE SERVER Exchange server is a mail server, we can send and receive mail from one user to another user. Exchange server is the mail server of Microsoft.

3.11.1 Elements of Exchange Server Mail Server A server which helps to the users to send and receive mail is called mail server.

Mail Box A storage place where senders and receivers mails are stored.

3.11.2

Exchange Version Table 10: Exchange Server with different operating systems Exchange Version

Operating System

Exchange Server 5.5

WIN NT or 2000 server (without SP).

Exchange Server 2000

WIN NT or 2000 server (SP3,SP4) without (SP).

Exchange Server 2003

WIN 2000 Server or WIN2003 server (SP4) without SP.

Exchange server 2007

WIN2003 server or R2/WIN 2008 server with SP1.

Where SP stands for Service Pack. Service Pack are the services which are loaded externally to remove some bugs that come during installation of server CD.

3.11.3 Requirements for Exchange Server Protocols Required •

POP3 (Post Office Protocol) This protocol is used for receiving e- mails.

•

IMAE4 (Internet Messaging Access Protocol) This protocol is advance version of POP, this is also used to receive mail.

•

LMTP (Local Mail Transfer Protocol)/SMTP (Simple Mail Transfer Protocol) This protocol is used to send mails.

•

NNTP (Network News Transfer protocol) This protocol is used for transferring messages on internet.

Hardware Requirements •

Processor: min. 133MHz Rec. 733MHz

•

RAM:

min. 256MB

Rec. 512MB

Other Requirements •

OS: 2k or 2k3 Server

•

NTFS partition

•

Static IP address

•

Active Directory

•

DNS installation with AD zone

•

IIS installed with ASP.net, SMTP, NNTP and www service

3.12 Open System Interconnection (OSI) Model OSI model is the layer approach to design, develop and implement network. OSI provides following advantages: (i)

Development of new technology will be faster.

(ii)

Devices from multiple vendors can communicate with each other.

(iii)

Implementation and troubleshooting of network will be easy.

3.12.1 Description of Different Layers Application Layer Application layer accepts data and forward into the protocol stack. It creates user interface between application software and protocol stack.

Presentation Layer This layer decides presentation format of the data. It also able to performs other function like compression/decompression and encryption/decryption.

Session Layer This layer initiate, maintain and terminate sessions between different applications.

Due to this layer multiple application software can be executed at the same time.

Transport Layer Transport layer is responsible for connection oriented and connection less communication. Transport layer also performs other functions like (i)

Error checking

(ii)

Flow Control Buffering Windowing Multiplexing

(iii)

Sequencing

(iv)

Positive Acknowledgement

(v)

Response

(vi) Network Layer This layer performs function like logical addressing and path determination. Each networking device has a physical address that is MAC address. But logical addressing is easier to communicate on large size network.

Logical addressing defines network address and host address. This type of addressing is used to simplify implementation of large network. Some examples of logical addressing are: - IP addresses, IPX addresses etc.

Network layer has different routing protocols like RIP, EIGRP, BGP, and ARP etc. to perform the path determination for different routing protocol.

Network layer also perform other responsibilities like defining quality of service, fragmentation and protocol identification.

Data Link Layer The functions of Data Link layer are divided into two sub layers •

Logical Link Control

•

Media Access Control

(i)

Logical Link Control defines the encapsulation that will be used by the NIC to delivered data to destination. Some examples of Logical Link Control are ARPA (Ethernet), 802.11 wi-fi.

(ii)

Media Access Control defines methods to access the shared media and establish the identity with the help of MAC address. Some examples of Media Access Control are CSMA/CD, Token Passing.

Physical Layer Physical Layer is responsible to communicate bits over the media this layer deals with the standard defined for media and signals. This layer may also perform modulation and demodulation as required.

3.13 ROUTERS 13.13.1 Router Architecture and its Key Component

LAN

Processor I/O Controller Memory Controller

RAM

BIOS ROM

WAN Ports

Flash RAM O/S

Incomplete IOS

IOS

NVRAM Startup Configuration

Fig 18 : Architecture of router Processor Speed: - 20 MHz to 1GHz Architecture: - RISC Reduce Instruction set computer Manufacturers: - Motorola, IBM, Power PC, Texas, Orion, Intel.

Flash RAM Flash memory is just like a hard copy of the computer. Flash RAM is the permanent read/write memory. This memory is used to store one or more copies of router O/S. Router O/S is also called IOS (Internetwork Operating System).The size of Flash RAM in the router is 4MB to 256MB. This memory is Electrically Erasable Programmable Read Only Memory (EEPROM).

NVRAM NVRAM is a “Non Volatile Random Access Memory”. It is used to store the startup configuration of the Router. It is on chip RAM, its size is 32kb.

RAM (Random Access Memory)

It is a volatile memory. All the activities we do are stored in RAM,this means that it holds the running configuration. RAM of the router is divided into two logical parts.

•

Primary RAM

•

Shared RAM

Primary RAM Primary RAM is used for: (i)

Running copy of IOS.

(ii)

Running configuration

(iii)

Routing table

(iv)

Address Resolution Protocol (ARP) table (IP address to MAC address)

(v)

Processor & other data structure

Shared RAM Shared RAM is used as a buffer memory to shared the data received from different interfaces. Size of RAM in a router may vary from 2 MB to 512 MB. The types of memory that may be present in a RAM are: (i)

DRAM -> Dynamic RAM

(ii)

EDORAM -> Extended Data Out RAM

(iii)

SDRAM -> Synchronous Dynamic RAM

ROM (Random Access Memory) It has four components: •

POST (Power on Self Test) It performs hardware testing.

•

BOOT Strap Boot strap specifies from where and which inter operating system is to be

loaded.

•

Mini IOS Cisco 2500, 1600

•

ROM MOW

3.13.2

Router Interfaces & Ports

Interface is used to connect LAN networks or wan networks to the router.

Interface will use protocol stacks to send/receive data. Ports are used for the configuration of routers. Ports are not used to connect different networks. The primary purpose of port is the management of router.

3.13.2.1

Router Interface

Table 11: Router interfaces and connectors

AUI – Attachment Unit Interface EPABX – Electronic Private Automatic Branch PSTN – Public Services Telephone Network 3.13.2.2 Router Ports Table 12: Router Ports

3.13.3

Modes of Router

When we access router command prompt the router will display different modes.

According to the modes, privileges and rights are assigned to the user.

User mode Router> In this mode, we can display basic parameter and status of the router we can test connectivity and perform telnet to other devices. In this mode we are not able to change and save router configuration.

Privileged mode Router# In this mode, we can display all information, configuration, perform administration task, debugging, testing and connectivity with other devices. We are not able to perform here configuration editing of the router.

The command to enter in this mode is ‘enable’. We have to enter enable password or enable secret password to enter in this mode. Enable secret has more priority

than enable password. If both passwords are configured then only enable secret will work.

Global configuration Route(config)# This mode is used for the configuration of global parameters in the router. Global parameters applied to the entire router. All the changes are performed in this mode. But here we cannot see and save the changes.

For e.g: - router hostname or access list of router, password, Banner, Routing, Security.

The command to enter in this mode is ‘configure terminal’

Line configuration mode In this mode we can set the password of the user mode, i.e to set user mode password .This mode is used to configure lines like console, vty and auxiliary. There are main types of line that are configured. (i)

Console Router(config)#line console 0

(ii) Auxiliary Router(config)#line aux 0 (iii) Telnet or vty Router(config)#line vty 0 4

Interface configuration mode In this mode we can set ip addresses of the interfaces. This mode is used to configure router interfaces. For e.g:- Ethernet, Serial, BRI etc.

Router(config)#interface <type> <number> Router(config)#interface serial 1

Routing configuration mode This mode is used to configure routing protocol like RIP, EIGRP, OSPF etc.

Router(config)#router <protocol> [<option>]

Router(config)#router rip Router(config)#router eigrp 10

3.13.4

Configuring Password

There are five types of password available in a router

Console Password router#configure terminal router(config)#line console 0 router(config-line)#password <word> router(config-line)#login router(config-line)#exit To erase password do all steps with no command.

Vty Password router>enable router#configure terminal router(config)#line vty 0 4 router(config-line)#password <word> router(config-line)#login router(config-line)#exit

Auxiliary Password router#configure terminal router(config)#line Aux 0 router(config-line)#password <word> router(config-line)#login router(config-line)#exit

Enable Password router>enable router#configure terminal

router(config)#enable password <word> router(config)#exit

Enable Secret Password Enable Password is the clear text password. It is stored as clear text in configuration where as enable secret password is the encrypted password.

Router>enable Router#configure terminal Router(config)#enable secret <word> Router(config)#exit

Encryption all passwords All passwords other than enable secret password are clear text password. The command to encrypt all password are Router#configure terminal Router(config)#service password-encryption

3.13.5 Managing Configuration There are two types of configuration present in a router (i)

Startup Configuration

(ii)

Running Configuration

Startup configuration is stored in the NVRAM. Startup configuration is used to save settings in a router. Startup configuration is loaded at the time of booting in to the Primary RAM. Running Configuration is present in the Primary RAM wherever we run a command for configuration, this command is written in the running configuration.

To save configuration Router#copy running-configuration startup-configuration Or Router#write

To abort configuration Router#copy startup-configuration running-configuration

To display running-configuration Router#show running-configuration

To display startup configuration Router#show startup-configuration

Configuring Host Name Router#configure terminal Router(config)#hostname <name> <name>#exit or end or /\z Router#config terminal Router(config)#hostname r1 R1(config)#

Configuration Interfaces Interfaces configuration is one of the most important part of the router configuration. By default, all interfaces of Cisco router are in disabled mode. We have to use different commands as our requirement to enable and configure the interface.

Router#configure terminal Router(config)#interface <type> <no> Router(config-if)#ip address <ip> <mask> Router(config-if)#no shutdown Router(config-if)#exit

To display interface status Router#show interfaces (to show all interfaces) Router#show interface <type> <no> This command will display following parameters about an interface (1)

Status

(2)

Mac address

(3)

IP address

(4)

Subnet mask

(5)

Hardware type / manufacturer

(6)

Bandwidth

(7)

Reliability

(8)

Delay

(9)

Load ( Tx load Rx load)

(10)

Encapsulation

(11)

ARP type (if applicable)

(12)

Keep alive

Configuring optional parameter on WAN interface Router#configure terminal Router(config)#interfac <type> <no> Router(config-if)#encapsulation <protocol> Router(config-if)#clock rate <value> Router(config-if)#end

Command displaying history of Router • To display commands present in history Router#show history

• To display history size Router#show terminal

• To change history size Router#config terminal Router(config)#line console 0 Router(config-if)#history size <value(0-256)> Router(config-if)#exit

Configuring Banners Banners are just a message that can appear at different prompts according to the type.

Different banners are: •

Message of the day (motd) This banner appear at every access method

•

Login Appear before login prompt

•

Exec Appear after we enter to the execution mode

•

Incoming Appear for incoming connections

Syntax:Router#config terminal Router(config)#banner

<type>

<delimation

char>Text

Massage

<delimation char> Router(config)#

Example Router#config terminal Router(config)#banner motd $ This router is distribution 3600 router connected to Reliance $ Router(config)#

To set time in router We can configure router clock with the help of two methods: (i)

Configure clock locally

(ii)

Configure clock on NTP server (Network Time Protocol)

Router does not have battery to save the clock setting. So that clock will reset to the default on reboot.

To display clock Router#show clock

To configure clock Router#clock set hh:mm:ss day month year Router#clock set 7:15:10 9 June 2009

To configure clock from NTP server Router#config terminal Router(config)#ntp server <IP address> Router(config)#exit C:\>ping pool.ntp.org To get ntp server ip from internet C:\>route print

3.14

SUBNETTING Subnetting is a process or a technique to divide large and complex networks into

smaller parts or smaller networks and each network is called as subnet. Subnetting is done to reduce the wastage of IP addresses ie instead of having a single huge network for an organization smaller networks are created within a given huge network. Subnetting allows the user to create multiple logical networks within a single Class A, B or C based networks.

In subnetting, the IPv4 address is broken into two parts; network id and host id.

This process borrows bits from the host id field. In this process, the network size does not shrink but the size of hosts per network shrinks in order to include sub-networks within the network.

3.14.1

Advantages of subnetting

•

Size of the physical networks is reduced and hence easy to manage.

•

Reduce network traffic.

•

Easy to troubleshoot.

•

Reduce the wastage of IP address.

Subnet Mask A subnet mask specifies the part of IP address that is to be used for identifying a sub network. A subnet mask when logically ANDed with IPaddress provides a 32- bit network address. This binary address gives the first address in the subnet block specified in the large network.

Default Mask Classfull addresses consists of three classes; Class A, Class B, Class C used for subnet.Each class has a default subnet mask C lass A consists of eight 1s in the network address field and 24 0s in remaining field, Class B consists of 16 1s in network address field and 16 0s in remaining field, and Class C cointains 24 1s in the network address field and remaining 8 bytes as 0s. the default address mask in binary and dotted-decimal is shown in the table

To Calculate the Subnet Mask 1. Identify the class of address assigned. For this example the class of IP address is Class B.

2. check the default address mask for the appropriate class and convert it to binary format .for this example the default address mask is 255.255.0.0 and the equivalent binary format is; 11111111.11111111.00000000.00000000 3. check the no. of 1s in the default mask. E.g this address contains 16 1s in class B, 16 bits 2 octat are for net id and the last 16 bits 2 octates are for host id.

4. now if we need 9 subnets. This no. 9 is not a power of 2. the next no. that is power of 2 and greater than 2 is 16. So, we require 4 extra 4 extra 1s in the network field which has to be borrowed from the host id field.

5. the total no. of 1s is 16+4=20, as 16 1s are from network id and 4 1s are of additional bits required for subnetwork. The no. of 0s in the n/w is 32-20=12. which defines whole address.

6. hence address is given as 11111111.11111111.11110000.00000000 and in decimal format can be given as 255.255.240.0 Table 14: decimal and binary values of subnet mask

Decimal Binary

00000000 0 128 192 224 240 248 252 254 255

10000000 11000000 11100000 11110000 11111000 11111100 11111110 11111111

3.14.2

Types of Subnetting

•

Fixed Length Subnet Mask (FLSM)

•

Variable Length Subnet Mask (VLSM)

Steps of Subnetting for FLSM For IP address 192.168.10.0 (Class C) Step 1: •

Identify the total no. of subnets 2^n = no.of subnets

•

Where n are the no.s and borrowed bytes from host ID portion. Let we are given that we have to make 4 subnets. Therefore 2^n =4 i.e n=2

Step 2: •

To idettify the total no. of the valid hosts for each subnet.

•

2^m-2= no.of valid hosts. Where m are the remaining no. of bits in host ID 2^62=62

Step 3: •

Calculate the subnet mask and range

•

Subnet

mask

for

n/w

192.168.10.0/26

11111111.11111111.11111111.1100000000 ie 255.255.255.192 •

range=> 256-192=64

step 4: •

Identify the total no of subnets, no. of valid hosts and the broadcast address.

Table 15: showing subnet mask, valid hosts, broadcast address Subnetwork

Valid Host

192.168.10.0

192.168.10.1

Broadcast Address to

192.168.10.63 192.168.10.64

192.168.10.65

192.168.10.63 to

192.168.10.126 192.168.10.12

192.168.10.129

8

192.168.10.190 192.168.10.193

192.168.10.19 2

192.168.10.254

192.168.10.127 to 192.168.10.191 to 192.168.10.255

is

VLSM In VLSM to allocate IP addresses to subnets depending upon the no. of hosts. The network having more no of hosts is given priority and the one having least no of host comes at last and for each network the subnet is assigned separately. As in the scenario given:

Fig 19: variable subnet mask 3.15 TELNET Telnet stands for terminal network, telephone network, terminal encapsulation on the network. Purpose of Telnet is to access the remote device in order to configure it. It provides textual access of the remote device. It uses the services of TCP. Telnet service is used where small bandwidth is low. It provides textual access of the remote device. Port number of Telnet is 23.

3.15.1 To Access the Device Remotely For this purpose we have to assign the IP addresses to the PCs and the interfaces.

For Telnet the Routers are to be configured with RIP version1 , so that the device can

ping each other. Also DCE cable is used to connect the Routers. The serial link should have the speed of 64K also apply vty password and enable secret password. Set up the Routers so that they can manage via Telnet.

First of all select the PCs and the routers connect the ports to the router, double click on router, switch off the router if it is on. Then select the serial port according to the routers, switch on the router. Select the cable to connect the Routers. Router to Router connections are made by the serial cable, so go on first Router select the serial port as s0/1/0 in the scenario, then go to the other Router and connect the serial cable at interface s1/0. Accordingly connect the third Router with interfaces s1/1 and s1/2.

Now connect the PCs to the routers, to do this first select the console cable, click on the PC select RS232 option, then connect it on the Router and select console cable. Now select cross- over cable on the PC select Fast Ethernet option and on the Router select f0/0 option now as the PCs and Routers are connected to each other assign IP addresses to the PCs and the Routers. According to the fig set the IP addresses of the PCs→ double click on the PC→ choose the option of desktop→ IP configuration. Now set the IP address, subnet mask, and the default gateway. Like wise set the IP address of all the PCs. Now set the IP address of the interfaces of router.

3.15.2 Commands to assign IP addresses to the interfaces: At Router1: Router> Router>enable Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 10.0.0.1 255.0.0.0 Router(config-if)#no shutdown

Fig 20: scenario of Telnet Router# Router#configure terminal Router(config)#interface s0/1/0 Router(config-if)#ip address 40.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown Now to check the assigned IPaddresses to the interfaces the command used is Router#show ip interface brief

At router 2: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 20.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router#

Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 40.0.0.2 255.0.0.0 Router(config-if)#no shutdown Router#configure terminal Router(config)#interface s1/1 Router(config-if)#ip address 50.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router(config)#interface s1/1 Router(config-if)#clock rate 64000 Router(config-if)#no shutdown

At router 3: Router#configure terminal Router(config)#interface f0/0 Router(config-if)#ip address 30.0.0.1 255.0.0.0 Router(config-if)#no shutdown Router# Router#configure terminal Router(config)#interface s1/0 Router(config-if)#ip address 50.0.0.2 255.0.0.0 Router(config-if)#no shutdown

To Telnet a device from Router At all the Routers use these commands Router(config)#line vty 0 4 Router(config-line)#password cobra Router(config-line)#login Router(config)#enable password cobra Router(config)#enable secret cobra1

To telnet a device from router Router#telnet <IP> Or Router>telnet <IP>

To exit from telnet session Router#exit

To exit from a hanged telnet session Ctrl+shft+6 Or Router#disconnect

To display connected session Router#show sessions This command shows those sessions, which are created or connected by us.

If we want anyone can telnet our router without password then on the line vty type command “No Login”.

3.16 ROUTING Routing is a process or technique to identify the path from one network to another. Routers don’t really care about hosts—they only care about networks and the best path to each network.

To route the packet the router must know the following things: •

Destination network

•

Neighbour device from witch it can learn about remote Networking.

•

Possible number of routers to reach the destination.

•

Best route to reach the destination.

•

How to maintain & verify the routing information.

3.16.1 TYPES OF ROUTING •

Static routing.

•

Default routing.

•

Dynamic routing.

3.16.1.1 STATIC ROUTING In static routing an administrator specifies all the routes to reach the destination.

Static routing occurs when you manually add routes in each router’s routing table.By default, Static routes have an Administrative Distance (AD) of 1

Features  There is no overhead on the router CPU.  There is no bandwidth usage between routers.  It adds security, because the administrator can choose to allow routing access to certain networks only.

Advantages of static routing (1) Fast and efficient.

(2) More control over selected path.

(3) Less overhead for router.

(4) Bandwidth of interfaces is not consumed in routing updates.

Disadvantages of static routing (1) More overheads on administrator.

(2) Load balancing is not easily possible.

(3) In case of topology change routing table has to be change manually.

Syntax for Static Routing Router (config)# ip route <destination N/w> <Subnet mask> <Next

Hope- address or exit interface> [<administrative distance>Permanent].

To check the routing table of router Router # show ip route

Fig 21: scenario of static routing

Static routing of router (R1) Router(config)#ip route 20.0.0.0 255.0.0.0 40.0.0.2 Router(config)#ip route 30.0.0.0 255.0.0.0 40.0.0.2 Router(config)#ip route 50.0.0.0 255.0.0.0 40.0.0.2 Router(config)#interface so/1/0 Router(config)# clock rate 64000 Router # show ip route

Static routing of router (R2) Router(config)#ip route 10.0.0.0 255.0.0.0 40.0.0.1

Router(config)#ip route 30.0.0.0 255.0.0.0 50.0.0.2 Router#show ip route Router(config)#interface s1/0 Router(config)# clock rate 64000 Router(config)#interface s1/1 Router(config)#clock rate 64000 Router#show ip route

Static routing of router (R3) Router(config)#ip route 10.0.0.0 255.0.0.0 50.0.0.1 Router(config)#ip route 20.0.0.0 255.0.0.0 50.0.0.1 Router(config)#ip route 40.0.0.0 255.0.0.0 50.0.0.1 Router(config)#interface s1/0 Router(config)# clock rate 64000 Router#show ip route

3.16.1.2

DEFAULT ROUTING Default routing is used to send packets with a remote destination network

not in the routing table to the next-hop route.

Default routing is also a type of static routing which reduces the routing overhead & default routing is also used with stub networks. Stub networks are those having a single exit interface. Default routing is also used for unknown destination.

A special address is used to perform the default routing ie 0.0.0.0 The scenario for default routing is same and but the commands used at the routers having single exit interface like R1 and R3 have different commands.

At Router (R1) Router(config)#ip route 0.0.0.0 0.0.0.0 40.0.0.2 Router#show ip route

At Router (R3) Router(config)#ip route 0.0.0.0 0.0.0.0 50.0.0.1 Router#show ip route

3.16.1.3

DYNAMIC ROUTING Dynamic routing is when protocols are used to find networks and update

routing table on routers.

A routing protocol defines the set of rules used by router when it communicates routing information between neighbor routers. In dynamic routing, we will enable a routing protocol on router. This protocol will send its routing information to the neighbor router. The neighbors will analyze the information and write new routes to the routing table.

The routers will pass routing information receive from one router to other router also. If there are more than one path available then routes are compared and best path is selected. Some examples of dynamic protocol are: RIP, IGRP, EIGRP, OSPF There are two type of routing protocols used in internetwors:

• Interior Gateway Protocols (IGPs) IGPs are used to exchange routing information with routers in the same Autonomous System(AS) number. Routing which is performed within a single autonomous system is known as interior routing. The protocol that are used to perform this type of routing are known as IGP(Interior Gateway Protocol).

These protocols are:(i)

RIPv1 (Routing Information Protocol Version 1)

(ii)

RIPv2 (Routing Information Protocol Version 2)

(iii)

EIGRP (Enhanced Interior Gateway Routing Protocol)

(iv)

OSPF (Open Shortest Path First)

(v)

IS-IS (Intermediate System to Intermediate System)

• Exterior Gateway Protocols (EGPs) EGPs are used to communicate between different Autonomous System.

Protocol that used to do this type of routing are called exterior gateway protocols.

Autonomous System:- An autonomous system is a collection of networks under a common administrative domain, which basically means that all routers sharing the same routing table information are in the same AS.

3.16.2 Routing Protocol Basics

•

(i)

Administrative Distances

(ii)

Routing protocol

(iii)

Routing Loops

Administrative Distances The Administrative Distance (AD) is used to rate the trustworthiness of routing

information received on a router from a neighbor router. An Administrative Distance is an integer from 0 to 255, where 0 is the most trusted and 255 means no traffic will be passed via this route.

If a router receives two updates listing he sane remote network, the first thing the router checks is the AD. If one of the advertised routes has lower AD than the other, then the route with the lowest AD will be placed in the routing table.If both advertised routes to the same network have the same AD, then routing protocol metrics (such as hop count or bandwidth of the lines) will be used to find the best path to the remote network. The advertised route with the lowest metric will be placed in the routing table.

But if both advertised routes have the same AD as well as the same metrics, then the routing protocol will load-balance in the remote network.

Route Source

Default AD

Connected interface

0

Static Route

1

EIGRP

90

IGRP

100

OSPF

110

RIP

120

External EIGRP

170

Unknown 255

This route will never be used

3.16.2.1

Classes of Routing Protocols

There are three classes of Routing Protocol (i)

Distance vector protocol

(ii)

Link state protocol

(iii)

Hybrid protocol.

• Distance vector protocol The Distance-vector protocols find the best path to remote network by judging distance. Each time a packet goes through a router, that’s called a hop. The route with the least number of hops to the network is determined to be the best route. The vector indicates the direction to the remote network. They send the entire routing table to directly connected neighbors.

Ex: RIP, IGRP.  The distance-vector routing algorithm passes complete routing table contents to neighboring routers.  A router receiving an update from a neighbor router believes the information about remote networks without actually finding out for itself.  It’s possible to have network that has multiple links to the same remote network, and if that’s the case, the administrative distance is checked first. If the AD is the

same, the protocol will have to use other metrics to determine the best path to use to that remote network.

Fig 16: Routing table

Converged Network

Fig 23 : Routing table of covered networks •

Routing Loops

Distance-vector routing protocols keep track of any changes to the internet work by broadcasting periodic routing updates out all active interfaces. This broadcast includes the complete routing table.

Routing loops can occur because a every router isn’t updated simultaneously.

Routing Loops Example

Fig 24: Routing loops The interface to Network 5 fails. All routers know about Network 5 from Router E. Router A, in its tables, has a path to Network 5 through Router B. When Network 5 fails, Router E tells Router C. This causes Router C to stop routing to Network 5 through Router E. But Routers A, B, and D don’t know about Network 5 yet, so they keep sending out update information. Router C will eventually send out its update and cause B to stop routing to Network 5, but Routers A and D are still not updated. To them, it appears that Network 5 is still available through Router B with a metric of 3.The problem occurs when Router A sends out its regular 30-second “Hello, I’m still here—these are the links I know about” message, which includes the ability to reach Network 5 and now Routers B and D receive the wonderful news that Network 5 can be reached from Router A, so Routers B and D then send out the

information that Network 5 is available. Any packet destined for Network 5 will go to Router A, to Router B, and then back to Router A. This is a routing loop.

•

Link state protocol Also called shortest-path-first protocols, the routers each create three

separate tables. One keeps track of directly attached neighbors, one determines the topology of the entire internet work, and one is used as the routing tables. Link state routers know more about the internet work than any distance-vector routing protocol.

Link state protocols send updates containing the state of their own links to all other routers on the network Ex: OSPF •

Hybrid protocol Hybrid protocol use aspects of both distance-vector and link state protocol.

Ex: EIGRP

3.16.3

RIP (Routing Information Protocol) Routing Information Protocol is a true distance-vector routing protocol. It

is an IGB (Inter Gateway Protocol). It sends the complete routing table out to all active interfaces every 30 seconds to its immediate neighbour. This is slow convergence means that one router sends a request to other about its route or network get networks which are not assigned to it after all thee three routers have same networks, this process is repeated to send and receive request so it is called slow convergence RIP only uses hop count to determine the best way to remote network, but it has a maximum allowable hop count of 0-15 by default, meaning that 16 is deemed unreachable.

RIP version 1 uses only class full routing, which means that all devices in the network must use the same subnet mask.

RIP version 2 provides something called prefix routing, and does send subnet mask information with the route updates. This is called classless routing.

•

Hop Count It is a way of measurement. Hop count limit is15.This routing supports only 15

routers, if there is one more router in the network then this routing will fails.

•

Default administrative distance (120)

Timers of RIP (i)

Update timers.

(ii)

Hold timers.

(iii)

Invalid timers.

(iv)

Flush out timers.

Route update timer Router update timer sets the interval 30 seconds between periodic routing updates, in which the router sends a complete copy of its routing table out to all neighbors.

Router invalid timers A router invalid timer determines the length of time that must elapse 180 seconds before a router determines that a route has become invalid. It will come to this conclusion if it hasn’t heard any updates about a particular route for that period. When that happens, thee router will send out updates to all its neighbors letting them know that the route is invalid.

Hold-down timer This sets the amount of time during which routing information is suppressed.

Routers will enter into the hold-down state when an update packet is received that indicated the route is unreachable. This continues until entire an update packet is received with a better metric or until the hold-down timer expires. The default is 180 seconds.

Route flush timer Route flush timers’ sets the time between a route becoming invalid and its interval from the routing table 240 seconds. Before it’s removed from the table, the router notifies its neighbors of that route’s impending demise. The value of the route invalid timer must be less than that of the route flush timers.

Difference between RIPV1 & RIPV2

Steps to do routing (version 1) At router 1 Router(config)# router rip Router(config-router)#network 10.0.0.0 Router(config-router)#network 40.0.0.0

Router#show ip route

At router 2 Router(config)# router rip Router(config-router)#network 20.0.0.0 Router(config-router)# network 40.0.0.0 Router(config-router)# network 50.0.0.0 Router#show ip route

At router 3 Router(config)# router rip Router(config-router)#network 30.0.0.0 Router(config-router)# network 50.0.0.0 Router#show ip route

3.16.4 IGRP ( Interior Gateway Protocol) Interior Gateway Routing Protocol (IGRP) is a Cisco-proprietary distance-vector routing protocol. To use IGRP, all your routers must be Cisco routers. IGRP has a maximum hop count of 255 with a default of 100. IGRP uses bandwidth and delay of the line by default as a metric for determining the best route to an internetwork. Reliability, load, and maximum transmission unit (MTU) can also be used, although they are not used by default.

Table 18 : Difference between IGRP and RIP IGRP

RIP

Can be used in large internetworks

Works best in smaller networks

Uses an autonomous system number for Does not yse aytibiniys system numbers activation Gives a full route table update every 90 Gives full route table update every 30 seconds

seconds

Has an administrative distance of 100

Has an administrative distance of 120

Uses bandwidth and delay of the line as Uses only hop count to determine the best metric (lowest composite metric),with a path to a remote network, with 15 hops maximum hop count of 255

being the maximum

IGRP Timers To control performance, IGRP includes the following timers with default settings: •

Update timers These specify how frequently routing-update messages should be sent. The

default is 90 seconds.

•

Invalid timers These specify how long a router should wait before declaring a route invalid if it

doesn’t receive a specific update about it. The default is three times the update period.

•

Hold down timers These specify the hold down period. The default is three times the update timer

period plus 10 seconds.

• Flush timers These indicate how much time should pass before a route should be flushed from the routing table. The default is seven times the routing update period. If the update timer is 90 seconds by default, then 7 × 90 = 630 seconds elapse before a route will be flushed from the route table.

At Router 1 R1(config)#router igrp 10 R1(config-router)#network 10.0.0.0 R1(config-router)#network 40.0.0.0 R1#show ip route

At Router 2 R2(config)#router igrp 10 R2(config-router)#network 40.0.0.0 R2(config-router)#network 20.0.0.0 R2(config-router)#network 50.0.0.0 R2#show ip route

At Router 3 R1(config)#router igrp 10 R1(config-router)#network 30.0.0.0 R1(config-router)#network 50.0.0.0 R1#show ip route

3.16.5

EIGRP(Enhanced Interior Routing Protocol) Enhanced IGRP (EIGRP) is a classless, enhanced distance-vector protocol

that gives us a real edge over IGRP. Like IGRP, EIGRP uses the concept of an autonomous system to describe the set of contiguous routers that run the same routing protocol and share routing information. But unlike IGRP, EIGRP includes the subnet mask in its route updates. The advertisement of subnet information allows us to use VLSM and summarization when designing our networks.

EIGRP is sometimes referred to as a hybrid routing protocol because it has characteristics of both distance-vector and link-state protocols. It sends traditional distance-vector updates containing information about networks plus the cost of reaching them from the perspective of the adverting router. EIGRP has a maximum hop count of 255.

Powerful features that make EIGRP a real standout from IGRP

•

Support for IP, IPX, and AppleTalk via protocol-dependent modules Considered classless (same as RIPv2 and OSP

•

Support for VLSM/CIDR

•

Support for summaries and discontiguous networks

•

Efficient neighbor discovery

•

Communication via Reliable Transport Protocol (RTP)

•

Best path selection via Diffusing Update Algorithm (DUAL) Cisco calls EIGRP a distance vector routing protocol, or sometimes an

advanced distance vector or even a hybrid routing protocol. EIGRP supports different Network layer protocols through the use of protocol-dependent modules (PDMs). Each EIGRP PDM will maintain a separate series of tables containing the routing information that applies to a specific protocol. It means that there will be IP/EIGRP tables, IPX/EIGRP tables, and AppleTalk/EIGRP tables.

Neighbor Discovery Before EIGRP routers are willing to exchange routes with each other, they must become neighbors. There are three conditions that must be met for neighborship establishment:  Hello or ACK received  AS numbers match  Identical metrics (K values) To maintain the neighborship relationship, EIGRP routers must also continue receiving Hellos from their neighbors. EIGRP routers that belong to different autonomous systems (ASes) don’t automatically share routing information and they don’t become neighbors.

The only time EIGRP advertises its entire routing table is when it discovers a new neighbor and forms an adjacency with it through the exchange of Hello packets. When this happens, both neighbors advertise their entire routing tables to one another. After

each has learned its neighbor’s routes, only changes to the routing table are propagated from then on.

EIGRP maintains three tables containing information about the internetworks. (i) Neighbor Table Records information about routers with whom neighborship relationships have been formed. (ii) Topology Table Stores the route advertisements about every route in the internetwork received from each neighbor.

EIGRP Metrics Another really sweet thing about EIGRP is that unlike many other protocols that use a single factor to compare routes and select the best possible path, EIGRP can use a combination of four: •

Bandwidth

•

Delay

•

Load

•

Reliability

3.16.6 OSPF (Open Shortest Path First) Open Shortest Path First (OSPF) is an open standards routing protocol that’s been implemented by a wide variety of network vendors, including Cisco. This works by using the Dijkstra algorithm. First, a shortest path tree is constructed, and then the routing table is populated with the resulting best paths. OSPF converges quickly, although perhaps not as quickly as EIGRP, and it supports multiple, equal-cost routes to the same destination.

But unlike EIGRP, it only supports IP routing.

OSPF is an IGP protocol. It is a link state routing protocol. It is supported by many operating systems. Its default AD is 110, hop count limit is unlimited.

It is classless routing protocol, supports VLSM/CIDR. By default the highest IP address of interface will be elected as Router id.

OSPF provides the following features 

Consists of areas and autonomous systems



Minimizes routing update traffic



Allows scalability



Supports VLSM/CIDR



Has unlimited hop count



Allows multi-vendor deployment (open standard) OSPF is supposed to be designed in a hierarchical fashion, which basically means

that you can separate the larger internetwork into smaller internetworks called areas. This is the best design for OSPF. The reasons for creating OSPF in a hierarchical design include: •

To decrease routing overhead

•

To speed up convergence

•

To confine network instability to single areas of the network Each router in the network connects to the backbone called area 0, or the

backbone area. OSPF must have an area 0, and all routers should connect to this area if at all possible. But routers that connect other areas to the backbone within an AS are called Area Border Routers (ABRs). Still, at least one interface must be in area 0.

OSPF runs inside an autonomous system, but can also connect multiple autonomous systems together. The router that connects these ASes together is called an Autonomous System Boundary Router (ASBR).

OSPF Terminology •

Link

A link is a network or router interface assigned to any given network. When an interface is added to the OSPF process, it’s considered by OSPF to be a link.

•

Router ID The Router ID (RID) is an IP address used to identify the router. Cisco chooses

the Router ID by using the highest IP address of all configured loopback interfaces. If no loopback interfaces are configured with addresses, OSPF will choose the highest IP address of all active physical interfaces.

•

Neighbors Neighbors are two or more routers that have an interface on a common

network,such as two routers connected on a point-to-point serial link.

•

Adjacency An adjacency is a relationship between two OSPF routers that permits the direct

exchange of route updates. OSPF is really picky about sharing routing information— unlike EIGRP, which directly shares routes with all of its neighbors. Instead, OSPF directly shares routes only with neighbors that have also established adjacencies. And not all neighbors will become adjacent—this depends upon both the type of network and the configuration of the routers.

OSPF Topologies database The topology database contains information from all of the Link State Advertisement packets that have been received for an area. The router uses the information from the topology database as input into the Dijkstra algorithm that computes the shortest path to every network. LSA packets are used to update and maintain the topology database.

A Link State Advertisement (LSA) is an OSPF data packet containing link-state and routing information that’s shared among OSPF routers. There are different types of LSA packets. An OSPF router will exchange LSA packets only with routers to which it has established adjacencies.

A designated router (DR) is elected whenever OSPF routers are connected to the same multi-access network. A prime example is an Ethernet LAN.

A backup designated router (BDR) is a hot standby for the DR on multi-access links The BDR receives all routing updates from OSPF adjacent routers, but doesn’t flood LSA updates.

OSPF areas An OSPF area is a grouping of contiguous networks and routers. All routers in the same area share a common Area ID. Broadcast (multi-access) Broadcast (multi-access) networks such as Ethernet allow multiple devices to connect to (or access) the same network, as well as provide a broadcast ability in which a single packet is delivered to all nodes on the network. In OSPF, a DR and a BDR must be elected for each broadcast multi-access network.

Non-broadcast multi-access Non-Broadcast Multi-Access (NBMA) networks are types such as Frame Relay, X.25, and Asynchronous Transfer Mode (ATM). These networks allow for multi-access, but have no broadcast ability like Ethernet. So, NBMA networks require special OSPF configuration to function properly and neighbor relationships must be defined.

•

Point-to-point Point-to-point refers to a type of network topology consisting of a direct

connection between two routers that provides a single communication path. The point-topoint connection can be physical, as in a serial cable directly connecting two routers, or it can be logical.

•

Point-to-multipoint Point-to-multipoint refers to a type of network topology consisting of a series of

connections between a single interface on one router and multiple destination routers. All of the interfaces on all of the routers sharing the point-to-multipoint connection belong to the same network. As with point-to-point, no DRs or BDRs are needed.

SPF Tree Calculation Within an area, each router calculates the best/shortest path to every network in that same area. This calculation is based upon the information collected in the topology database and an algorithm called shortest path first (SPF) OSPF uses a metric referred to as cost. A cost is associated with every outgoing interface included in an SPF tree. The cost of the entire path is the sum of costs of the outgoing interfaces along the path.

Cisco uses a simple equation of 108/ bandwidth.The bandwidth is the configured bandwidth for the interface. Using this rule, a 100Mbps Fast Ethernet interface would have a default OSPF cost of 1 and a 10Mbps Ethernet interface would have a cost of 10.

An interface set with a bandwidth of 64,000 would have a default cost of 1563.

Benefits of OSPF (i)

Minimum routing updates.

(ii)

Priorities on all the CISCO routers the priority is 1.

(iii)

The routers having highest IP address become BRD(Border Destination Router)

Steps to apply OSPF Syntax: Router(config)#router ospf <ospf process id> Router(config-router)#network <network address> <wild card mask> area <area number>

Fig 25: OSPF Scenario

At Router r1 Router(config)#router ospf 1 Router(config-router)#network 10.0.0.0 0.255.255.255 area 0 Router(config-router)#network 10.0.0.0 0.255.255.255 area 0 Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router#show ip route

At Router r1 Router(config)#router ospf 2 Router(config-router)#network

20.0.0.0

0.255.255.255

Router(config-router)#network 40.0.0.0 0.255.255.255 area 0 Router(config-router)#network 50.0.0.0 0.255.255.255 area 0 Router(config)#interface s0/1/0 Router(config-if)#clock rate 64000 Router#show ip route

At Router r3 Router(config)#router ospf 1 Router(config-router)#network 30.0.0.0 0.255.255.255 area 0 Router(config-router)#network 50.0.0.0 0.255.255.255 area 0 Router#show ip route

area

0

3.17 LAN SWITCHING 3.17.1 SWITCH Switches are generally used to segment a large LAN smaller segments. Smaller switches such as the Cisco Catalyst 2924XL have 24 ports capable of of creating 24 different network segment for the LAN. Larger switches such as the Cisco Catalyst 6500 can have hundreds of ports. Switches can also be used to connect LANs with different media, for example, a 10 Mbps Ethernet LAN and 100 Mbps Ethernet LAN can be connected using a switch. Some switches support cut through switching, witch reduces latency and delays in the network, while bridges support only store-and-forward traffic switching. Finally switches reduce collision

on network segment . A switch is a

networking device which filters and forward packets through the network. It is a layer 2 device. It is more advanced then hub but not as advanced as router.The basic function of a switch is to manage the signal flow. When the switch is open, it allows the signal to flow through it and when it is closed, it stopes the signal to flow. Switch connects separate LAN segment. It allows multiple system to transmit simultaneously. A switch is a hardware device that filters and forward data packets between network segments.

Ethernet switches are used in LAN to create Ethernet networks. Switches forward the traffic on the basis of MAC address. Switches maintain a switching table in which MAC addresses and port numbers are used to perform switching decision.

WORKING OF SWITCH When switches receives data from one of connected devices, it forward data only to the port on witch the destinated system is connected.It use the media access Control (MAC) address of the device to determine the correct port.The MAC address is a uniqe number that is programed in to every Network Interface Card(NIC). Concider, device A wants to send data to device B.When device A passes the data, switch receives it. Switch than cecks the MAC address of the destination system. It then transfer data to device B

only instead of brodcasting to all the devices. By forwarding data only to the system to witch the data is addressed, switch decreases the amount of traffic on each network link.

SWITCHING METHODS There are three types of switching method: •

Store-and-forward switching The entire frame is received and the CRC is computed and verified before

forwarding the frame. If the frame is too short (i.e. less than 64 bytes including the CRC), too long (i.e. more than 1518 bytes including the CRC), or has CRC error, it will be discarded.

It has the lowest error rate but the longest latency for switching. However, for high-speed network (e.g. Fast Ethernet or Gigabit Ethernet network), the latency is not significant. It is the most commonly used switching method, and is supported by most switches.

•

Cut-through switching It is also known as Fast Forward switching. A frame is forwarded as soon as the destination MAC address in the header has been received (the 1st 6 bytes following the preamble). It has the highest error rate (because a frame is forwarded without verifying the CRC and confirming there is no collision) but the shortest latency for switching

•

Fragment-free switching ( Modified Cut-through switching ) A frame is forwarded after the first 64 bytes of the frame have been received. Since a collision can be detected within the first 64 bytes of a frame, fragment-free switching can detect a frame corrupted by a collision and drop it.Therefore, fragment-free switching provides better error checking than cutthrough switching.

The error rate of fragment-free switching is above store-and-forward switching and below cut-through switching. The latency of fragment-free

switching is shorter than store-and- forward switching and longer than cutthrough switching.

NOTE: Bridges only support store-and-forward switching. Most new switch models also use store-and-forward switching. However, it should be noted that Cisco 1900 switches use fragment-free switching by default.

Types of switch based on OSI model

•

(i)

Layer-2 switch

(ii)

Layer-3 switch

Layer-2 Switching Layer-2 switching is hardware based, which means it uses the MAC

address from the host NIC card to filter the network traffic. Layer-2 switch can be considered as multi- port bridge.

Layer 2 switches are fast because they do not look at the network layer header information, instead it looks at the frames hardware address before deciding to either forward the frame or drop it.

Limitations of Layer 2 Switching With bridge the connected networks are still one large broadcast domain.

Layer 2 switch cannot break the broadcast domain, this cause performance issue which limits the size of your network. For this one reason the switch cannot completely replace routers in the internetwork.

3.17.1.1

VLAN (Virtual LAN)

VLAN provides Virtual Segmentation of Broadcast Domain in the network. The devices, which are member of same Vlan, are able to communicate with each other. The

devices of different Vlan may communicate with each other with routing. So that different Vlan devices will use different n/w addresses.

Vlan provides following advantages: •

Logical Segmentation of network

•

Enhance network security

Creating port based Vlan In port based Vlan, first we have to create a Vlan on manageable switch then we have to add ports to the Vlan. A Virtual LAN (VLAN) is a broadcast domain created based on the functional, security, or other requirements, instead of the physical locations of the devices, on a switch or across switches. With VLANs, a switch can group different interfaces into different broadcast domains. Without VLANs, all interfaces of a switch are in the same broadcast domain; switches connected with each other are also in the same broadcast domain, unless there is a router in between. Different ports of a switch can be assigned to different VLANs. A VLAN can also span multiple switches.

The advantages of implementing VLAN are •

It can group devices based on the requirements other than their physical locations.

•

It breaks broadcast domains and increases network throughput.

•

It provides better security by separating devices into different VLANs.

•

Since each VLAN is a separate broadcast domain, devices in different VLANs cannot listen or respond to the broadcast traffic of each other.

•

Inter-VLAN communication can be controlled by configuring access control lists on the router or Layer 3 switch connecting the VLANs.

Types of VLAN •

Static VLAN Assigning VLANs to switch ports based on the port numbers. It is easier to set

up and manage.

•

Dynamic VLAN Assigning VLANs to switch ports based on the MAC addresses of the

devices connected to the ports.

A VLAN management application is used to set up a database of MAC addresses, and configure the switches to assign VLANs to the switch ports dynamically based on the MAC addresses of the connected devices. The application used by Cisco switches is called VLAN Management Policy Server (VMPS).

Cisco switches support a separate instance of spanning tree and a separate bridge table for each VLAN.

A VLAN = A Broadcast Domain = Logical Network (Subnet)

VLAN Operation

Fig 26: VLAN Operation •

Each logical VLAN is like a separate physical bridge.

•

VLANs can span across multiple switches.

•

Trunks carry traffic for multiple VLANs.

•

Trunks use special encapsulation to distinguish between different VLANs.

VLAN links

There are two different types of links in a switched network: •

Access link

A link from Pc to switch is called as access link or A link that is part of only one VLAN. Therefore, a port connecting to an access link can be a member of only one VLAN. And the mode of port is called as access mode.

•

Trunk link A link from switch to switch or switch to router is called as trunk link. A 100

Mbps or 1000 Mbps point-to-point link that connects

switches or routers, and carries

frames of different VLANs . Therefore, a port connecting to a trunk link can be a member of multiple VLANs. All VLANs are configured on a trunk link by default. VLAN Trunking, by making use of frame tagging, allows traffic from different VLANs to transmit through the same Ethernet link (trunk link) across switches.

VLAN Trunking identifies the VLAN from which a frame is sent by tagging the frame with the source VLAN ID (12-bit long). This feature is known as frame tagging or frame identification. When there are multiple switches then we have to use trunk links to connect one switch with other. If we are not using trunk links then we have to connect one cable from each vlan to the corresponding vlan of the other switch.

With frame tagging, a switch knows which ports it should forward a broadcast frame (forward out the ports which have the same VLAN ID as the source VLAN ID). It also knows which bridge table it should use for forwarding an unicast frame (since a separate bridge table is used for each VLAN).

A frame tag is added when a frame is forwarded out to a trunk link, and is removed when the frame is forwarded out to an access link. Therefore, any device attached to an access link is unaware of its VLAN membership.

Commands to create Vlan Switch#vlan database Switch(vlan)#vlan <no.> [name <name of vlan>] Switch(vlan)#exit

Commands to configure ports for a Vlan By default, all ports are member of single vlan that is Vlan1. we can change vlan membership according to our requirement.

Switch(config)#interface <type> <no.> Switch(config-if)#switchport access vlan <no.> Switch(config-if)#exit

Commands to configure multiple ports in a vlan Switch(config)#interface range <type> <slot/port no. (space)–(space) port no.> Switch(config-if)#switchport access vlan <no.> Switch(config-if)#exit Example: - Suppose we want to add interface fast Ethernet 0/10 to 0/18 in vlan5 Switch(config)#interface range fastethernet 0/10 – 18 Switch(config-if)#switchport access vlan 5 Switch(config-if)#exit

To display mac address table Switch#show mac-address-table Vlan

Mac address

type

ports

20

00-08-a16-ab-6a-7b

dynamic

fa0/7

To Display Vlan and port membership Switch#show vlan brief

Command to make Trunk link Switch(config)#interface <type> <type number> Note :- Trunk mode should not be a member of any vlan port.

3.17.1.2 Vlan Trunking Protocol (VTP) With the help of VTP, we can simplify the process of creating Vlan. In multiple switches, we can configure one switch as VTP server and all other switches will be configured as VTP client. We will create Vlans on VTP server switch. The server will send periodic updates to VTP client switches. The clients will create Vlans from the update received from the VTP server.

VTP Operation •

VTP advertisements are sent as multicast frames.

•

VTP servers and clients are synchronized to the latest revision number.

•

VTP advertisements are sent every 5 minutes or when there is a change.

VTP Modes •

VTP server mode By default all the switches in this mode are in server mode. VTP server is a

switch in which we can create, delete or modify Vlans.yhe switch in this mode forwords the vlans to next switch. The server will send periodic updates for VTP clients.

•

VTP client mode On VTP client, we are not able to create, modify or delete Vlans. The switch

in this mode creates the vlans that are received from server mode switch.The client will receive and forward vtp updates. The client will create same Vlans as defined in vtp update.

•

VTP Transparent mode Transparent is a switch, which will receive and forward VTP update. It is able

to create, delete and modify Vlans locally. A vlan created in this mode cannot be forworded into next switch. A transparent will not send its own VTP updates and will not learn any information from received vtp update.

VTP configuration At Switch 1: •

Creat vlan

•

Port assignment

•

Trunk port

•

Switch vtp

Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun

At switch 2: Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun

At switch 3: Switch(config)#vtp mode server Switch(config)#vtp domain cisco Switch(config)#vtp password sun

Fig 27 : VTP Configuration

To see all the configurations Switch#show vtp password Switch#show vlan brief Switch#show vtp status •

Vtp version

•

Vtp domain

•

Vtp mode

•

Vtp pruning

•

Vtp reusion number

•

Maximum vlan supporting

•

Total no. of vlans

VTP Pruning Pruning is the VTP feature through which a trunk link can be automatically disable, for a particular Vlan if neighbor switch does not contain ports in that Vlan. Vlan1 is not prun eligible.

•

Increases available bandwidth by reducing unnecessary flooded traffic

•

Example: Station A sends broadcast, and broadcast is flooded only toward any switch with ports assigned to the red VLAN

Command to configure VTP Pruning We have to use only one command on VTP server for VTP Pruning.

Switch#configure terminal Switch(config)#vtp pruning Switch(config)#exit

Fig 28 : VTP Pruning

Spanning Tree Protocol When we connect multiple switches with each other and multiple path exist from one switch to another switch then it may lead to the switching loop in the network.

Multiple paths are used to create redundancy in the network. STP is only required when multiple path exist then there is possibility of loop in n/w.

Problems that occur with redundancy path (i)

Multiple copies of the frame will be received by destination.

(ii)

Frequent changes in the mac address table of switch.

(iii) A mac address may appear at multiple ports in a switch. (iv)

Packets may enter in the endless loop.

Spanning Tree Protocol will solve this problem by blocking the redundancy interface. So that only one path will remain active in the switches. If the primary path goes down then disabled link will become enable and data will be transferred through that path.

Spanning Tree Protocol Basics •

Spanning Tree Protocol or STP (IEEE 802.1d) is used to solve the looping problem.It runs on bridges and switches in a network. It implements a Spanning Tree Algorithm (STA), which calculates a loop-free topology for the network.

•

STP ensures that there is only one active path between any two network segments by blocking the redundant paths. A redundant path is used only when the corresponding active path failed. It is not used for load-balancing.

•

Because STP solves the looping problem by blocking one or more links in a network, the frames traveling between some source / destination devices may not be able to use the shortest physical path.

•

Bridges exchange STP information using messages called Bridge Protocol Data Units (BPDUs) through Layer 2 multicast.

3.18

Wi-Fi (WIRELESS FIDELITY) The term "Wi-Fi" suggests "Wireless Fidelity", compared with the long-

established audio recording term "High Fidelity" or "Hi-Fi". The term "Wi-Fi", first used commercially in August 1999. Wi-Fi is an IEEE standard 802.11.

3.18.1 Wireless LAN Wi-Fi is also known as wireless LAN. The name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. "Wi-Fi works with no physical wired connection between sender and receiver by using radio frequency (RF) technology, a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is

supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.

The Typical Range of a Wi-Fi LAN The range of a home Wi-Fi LAN depends on the wireless access point (WAP) or wireless router being used. Factors that determine a particular WAP or wireless router's range are: •

the specific 802.11 protocol employed

•

the overall strength of the device transmitter

•

the nature of obstructions and interference in the surrounding area A general rule of thumb in home networking says that 802.11b and 802.11g

WAPs and routers support a range of up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors. Another rule of thumb holds that the effective range of 802.11a is approximately one-third that of 802.11b/g.

Obstructions in home such as brick walls and metal frames or siding greatly can reduce the range of a Wi-Fi LAN by 25% or more. Because 802.11a employs a higher signalling frequency than 802.11b/g, 802.11a is most susceptible to obstructions.

Interference from microwave ovens and other equipment also affects range. 802.11b and 802.11g are both susceptible to these.

3.18.2

Wireless Standards

The different wireless standards that are used for IEEE 802.11 standard are

Fig 29:

IEEE 802.11 Standards

802.11 It was released in year 1997. The standard was original of 802.11. the max. data rate of this is 2Mbps and frequency of this is 2.4GHz and can cover upto 46m.

802.11a It was modified in year 1999. this is improved version of original standard.

Operates at the frequency of 5GHz, which is less crowded than 2.4GHz where telephones and microwaves may cause interference. Although the speed is up to 54Mbps, the range is only up to 75 feet or distance covered is 46m. 802.11a standard is incompatible with both 802.11b and g because it operates at a different frequency.

802.11b This standard was released in 1999. Operates on the 2.4GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet or a distance of 90m.Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors.

802.11g This standard was released in 2003. The max. data rate for the standard is 54Mbps.

It supports a frequency range of 2.4GHz, covers a distance of 90m.

802.11n

The latest version of IEEE 802.11 standard that is still in progress of development. The next generation of high-speed wireless networking, capable of delivering the range and capacity to support today's most bandwidth-hungry applications like streaming high definition video, voice, and music. Wireless-n is based on MIMO (Multiple Input, Multiple Output) technology, which uses multiple radios to transmit multiple streams of data over multiple channnels.

Operates in two modes of frequency 2.4GHz and 5.6GHz frequency band and can transmit data at speeds of up to 11Mbps within a range of up to 100-150 feet .

Wireless range can be affected by reflective or signal-blocking obstacles, such as mirrors, walls, devices and location, whether indoors or outdoors.

Wi-Fi is supported by many applications and devices

3.18.3

•

video game consoles

•

home networks

•

PDAs

•

mobile phones

•

major operating systems

•

other types of consumer electronics

Wireless Security

A common but unproductive measure to deter unauthorized users is to suppress the AP's SSID broadcast, "hiding" it. This is ineffective as a security method because the SSID is broadcast in the clear in response to a client SSID query. Another unproductive method is to only allow computers with known MAC addresses to join the network.

MAC address are easily spoofed. If the eavesdropper has the ability to change his MAC address, then he may join the network by spoofing an authorized address.

Wired Equivalent Privacy (WEP) encryption was designed to protect against casual snooping, but is now considered completely broken. Tools such as AirSnort or aircrack can quickly recover WEP encryption keys.

To counteract this in 2002, the Wi-Fi Alliance blessed Wi-Fi Protected Access (WPA) for wireless security. Though more secure than WEP, it has outlived its designed lifetime, has known attack vectors and is no longer recommended.

In 2004 the full IEEE 802.11i (WPA2) encryption standards were released. If used with a 802.1X server or in pre-shared key mode with a strong and uncommon passphrase WPA2 is still considered secure, as of 2009.

4.

CONCLUSION

General Conclusion Computer Networking is a very vast project in the present developing era of electronics and communication. Now a days, computers are used in a wider range. All the

organizations are using multiple computers within their departments to perform their day to day work. Computer network allows the user to share data , share folders and files with other users connected in a network. Computer Networking has bound the world in a very small area with it wide networking processes like LAN, MAN, WAN.

Applications •

Communication Field

•

Industries

•

Medical Field

•

Rearch Field

•

Organisations

•

School

•

Colleges

REFRENCES •

www.goole.com

•

www.jetkinginfotrain.com

•

www.microsoft.com

•

www.nythimes.com

•

www.digitech-engineers.com

•

Network Essentials module

•

4-in-1 MCSE study material

•

Introduction to Window Server2003

•

CISCO Cretified Network Associate

•

Faruk Husain