127.0.0.1 is simply an alias for the local server on your computer (usually 'localhost' although sometimes it can be 'linux'). You can usually use any 127.*.*.* address as well. If you don't have a local server installed it merely acts as a loopback address.

If the request times out either you have a firewall blocking incoming packets or you could try localhost (although this shouldn't make any difference as they point to the same thing).