is the standard IP address used for a loopback network connection.

This means that if you try to connect to, you are immediately looped back to your own machine. If you telnet, ftp, etc… to, you are connected to your own machine.

In other words, is you.

For example, if your system was named “hostname”, and you attempted to telnet to, you would see:

# telnet
Connected to hostname
Escape character is ‘^]’.

Another name for is localhost.

Although is the most commonly utilized address for localhost, any IP address in the 127.*.*.* range should also function in the same manner.