Date: 2012mar23 Keywords: loopback Q. What is IP-address 127.0.0.1 ? A. That's the IPv4 address of "localhost" -- or "this computer". On any nearly any computer (Windows, Mac, Linux) you should be able to use the "ping" command:

ping localhost

or

ping 127.0.0.1

And get a reply such as:

PING localhost.localdomain (127.0.0.1) 56(84) bytes of data. 64 bytes from localhost.localdomain (127.0.0.1): icmp_req=1 ttl=64 time=0.090 ms 64 bytes from localhost.localdomain (127.0.0.1): icmp_req=2 ttl=64 time=0.121 ms 64 bytes from localhost.localdomain (127.0.0.1): icmp_req=3 ttl=64 time=0.123 ms

This means your computer is able to communicate with itself (which is good). There are some TV shirts that say "There's no place like 127.0.0.1" meaning, of course, "there's no place like home".