An Introduction To 127.0.0.1 127.0.0.1 is an IP address utilized for a looplock network connection. What does this mean? If a user tries to connect to this IP address, they will be sent back to their computer. The address is also known as a localhost. The localhost is the computer.
How the Localhost Works If the command is relayed to the localhost, you would be hooked up to the system where the commands were sent out. For instance, suppose the computer is called “Joker”. If you telnet from the Joker computer to the localhost, a message will appear. It will attempt to hook up to the localhost. The localhost is employed in lieu of the computer hostname to be linked to. This IP address is the most wisely used localhost address. However, you can actually use any IP address provided it starts with 127. This means 127.*.*.* can be used as a localhost. Establishing a connection with the loopback address is similar to creating a connection with remote network computers. The only difference is you don’t have to deal with network interface hardware. For this reason it is widely utilized by software developers. It is also used by system administrators. It is often used for testing programs and apps. If the connection is IPv4, the computer’s loopback address will be the 127.*.*.*. The subnet mask is typically 255.0.0.0.
Internet RFC This IP addresses 127.*.*.*. are defined in RFC 330 as Special-Use IPv4 Addresses. The 127.0.0.0/8 block is defined as the Net host loopback address. If a higher level protocol sends a datagram anywhere in the block, it will be looped in the host. This is typically implemented with the 127.0.0.1 / 32 for looplock. However, addresses in the block must not be visible anywhere else in the network. There is also a localhost IPv6 version. In RFC 3513, it is defined as Internet Protocol Version 6 (IPv6) Addressing Architecture::1/128.
More Information about the Localhost In simple terms, the localhost means the computer. It is the hostname allocated loopback network interface address. The name is likewise a domain name. This will help prevent confusion with the hostname definition. In IPv6, the loopback IP address is ::1. The localhost is stated when one would usually use the computer hostname. For instance, a browser using an HTTP server to http://localhost will show the local website home page. This will be possible if the server is set up properly to work the loopback interface. The loopback address can also be used for linking up to a game server. It can also be used for the various inter-process communications. This facts about 127.0.0.1 indicate how fundamental and basic the localhost is to a system. That’s why it is so crucial for network administrators. References: http://en.wikipedia.org/wiki/Localhost http://www.tech-faq.com/localhost.html http://www.tech-faq.com/127-0-0-1.html http://www.mightyguide.net/127-0-0-1.html http://www.rolo.org/127-0-0-1.html