Page 1

補充 IP Version 6

P-1


章節內容 • IPv6 Addresses ─ Unicast ─ Multicast ─ Anycast

• Enabling IPv6 on Windows, Linux & Cisco Routers

P-2


IPv6 位址表示法 Format: • x:x:x:x:x:x:x:x where x is a 16-bit hexadecimal field – 2031:0000:130F:0000:0000:09C0:876A:130B – Case insensitive • Leading zeros in a field are optional: – 2031:0:130F:0:0:9C0:876A:130B • Successive fields of 0 are represented as ::, but only once in an address: – 2031:0:130F::9C0:876A:130B – 2031::130F::130B – FF01:0:0:0:0:0:0:1 => FF01::1 – 0:0:0:0:0:0:0:1 => ::1 – 0:0:0:0:0:0:0:0 => :: P-3


IPv6 位址分類 • Unicast: (one-to-one) (2000::/3)

• Multicast: (one-to-group) (FF00::/8)

• Anycast: (one-to-nearest)

P-4


IPv6 Addresses

P-5


IPv6 Unicast Addresses • Types of IPv6 unicast addresses: – Global unicast address : Starts with 2000::/3 and assigned by IANA – Link local address : Starts with FE80::/10 – Unique local addresses : Starts with FC00::/7

– Special-purpose addresses: • Unspecified (::/128) • Loopback (::1/128) • IPv4-mapped • IPv6 addressing rules are covered by multiple RFCs.

– Architecture defined by RFC 4291 P-6


IPv6 Unicast Addresses (I)

Global Unicast Addresses (RFC 3857) • Global unicast addresses are addresses for generic use of IPv6 • Interface identifier should be kept at 64 bits

P-7


Interface Identifiers Used to identify interfaces on a link • Must be unique on that link

• Can be globally unique Unicast addresses should have a 64-bit interface ID • Except for unicast addresses that start with binary 000 • Interface ID constructed in Modified EUI-64 format 128 bits Interface ID 64 bits P-8


Modified EUI-64 Format Ethernet MAC address (48 bits) 00

00

90

90

27

27

FF 64 bits version U/L bit

00

90

27

FF

FC

0F

17

FC

0F

FE FE

17

FC

0F

1 = Universally Unique

000000X0

where X =

X=1 Modified EUI-64 address

17

02

90

27

FF

0 = Locally Unique FE

17

FC

0F

 This format expands the 48-bit MAC address to 64 bits by inserting “FFFE” into the middle 16 bits.  To make sure that the chosen address is from a unique Ethernet MAC address, the U/L bit is set to 1 for global scope (0 for local scope). P-9


IPv6 Unicast Addresses (II)

Link-local Addresses  Have a scope limited to the link and are automatically configured on all IPv6 interfaces by using a specific link-local prefix FE80::/10 and a 64-bit interface ID.  Are used for automatic address configuration, neighbor discovery, and router discovery. Also used by many routing protocols.  Link-local addresses can serve as a way to connect devices on the same local network without needing global addresses. P-10


IPv6 Unicast Addresses (III) 128 bits Global ID

Interface ID

FD00::/8

Subnet ID

8 bits

16 bits

Unique local unicast addresses (RFC4193): • FC00::/7 ─ FC00::/8 planned to be globally managed ─ FD00::/8 assigned locally by network administration • For network in which only internal IPv6 communication is required • Not routable on the Internet P-11


IPv6 Unicast Addresses (IV) • Unspecified address: ─ 0:0:0:0:0:0:0:0 (::/128) ─ Used as a placeholder when no address is available (initial DHCP request, DAD) • Loopback address: ─ 0:0:0:0:0:0:0:1 (::1/128) ─ Same as 127.0.0.1 in IPv4 ─ Identifies itself

P-12


IPv6 Unicast Addresses (V) 80 bits

16 bits

32 bits

0

FFFF

IPv4 Address

0:0:0:0:0:FFFF:192.168.30.1 = ::FFFF:192.168.30.1 = ::FFFF:C0A8:1E01

IPv4-Mapped Addresses • Used to represent the addresses of IPv4 nodes as IPv6 addresses • Used for next-hop representation in Cisco IPv6 Provider Edge (6PE) and IPv6 VPN Provider Edge (6VPE) routers • Used in network stacks when both address families are processed internally as IPv6 (e.g., Linux) P-13


IPv6 Multicast Addresses (I) Multicast Addresses (FF::/8) • Multicast is used in the context of one-to-many • Explicit multicast scope is a new concept in IPv6 112 bits group ID 0 if permanent

1111 1111

F 8 bits

F

Flag = Flag

Scope

8 bits Scope =

1 if temporary 1 = Interface-Local 2 = Link-Local 3 = Subnet-Local 4 = Admin-Local 5 = Site-Local 8 = Organization E= Global P-14


IPv6 Multicast Addresses (II) Multicast Assigned Addresses (RFC 2375) • FF0X:: is reserved (X=0..F) • Inside this range, the following are assigned: Meaning

Scope

FF02::1

All nodes

Link-local

FF02::2

All routers

Link-local

Solicited-node

Link-local

FF05::1:3

All DHCP servers

Site-local

FF0X::127

Cisco-RP-ANNOUNCE

Any scope

FF02::1:FFXX:XXXX

P-15


IPv6 Anycast Addresses Anycast addresses: • • • • • •

Used in the context of one-to-nearest Assigned to more than one interface Allocated from the unicast address space Indistinguishable from regular unicast addresses Must be explicitly configured as anycast on the node All nodes with the same anycast address should behave the same way n bits

128-n bits

Prefix

Interface ID

P-16


Addressing Architecture

2000::/3 space

• This graph shows the IANA assignments of IPv6 addresses • X axis = full address space • Y axis = 0 or 1 if space is allocated

• 1 does not mean that space is used, only reserved by IANA

P-17


Required IPv6 Host Addresses An IPv6 host interface requires the following IPv6 addresses for proper operation: • • • •

A link-local address Loopback address (::1) All-nodes multicast address (FF02::1) Any additional unicast and anycast addresses configured (automatically or manually) • Solicited-node multicast address for each of its unicast and anycast addresses • Multicast address of all other groups to which the host belongs

P-18


Required IPv6 Router Addresses An IPv6 router interface requires the following IPv6 addresses for proper operation : • All of the required host addresses • All router multicast addresses (FF02::2) • Other unicast or anycast-configured addresses

P-19


Enabling IPv6 on Windows • Enable IPv6 support on Windows XP and Windows Server 2003: C:\>netsh interface ipv6 install

• Basic “netsh” commands: C:\>netsh netsh>interface netsh interface>ipv6 netsh interface ipv6>set address <interface> <prefix> or C:\>netsh interface ipv6 set address LAN 2001:db8:100::1 C:\>netsh interface ipv6>set route <destination> <gateway> C:\>netsh interface ipv6>set route ::0 LAN fe80::1

• Verification: ─ ipconfig ─ netsh interface ipv6 show addresses ─ route print -6 ─ netsh interface ipv6 show route

P-20


Enabling IPv6 on Linux • Adding IPv6 support to a running kernel: Host#modprobe ipv6

• Basic Configuration: Host#ifconfig <interface> ipv6 add <prefix>/<length> Host#ifconfig eth0 ipv6 add 2001:db8:100:12::10:17/64 Host#route –A inet6 add <destination> gw <gateway> Host#route –A inet6 add default gw fe80::1

• Verification: ─ ipconfig ─ route -6

P-21


Enabling IPv6 on Cisco Routers

0060.3e47.1530

P-22


Ch8-24

IPv6  

Travis Tai's PPT for IPv6

Read more
Read more
Similar to
Popular now
Just for you