Yes, the entire 127.* block acts as local loopback. This knowledge is far less widespread than 127.0.0.1, so feel free to replace it with say 127.4.65.234 (or whatever) when abusing n00bs and "hax0rs." Feel free to look up the RFC on it, it should confirm my position, although it may be so old as to use something like 127/24 notation. Unfortunately, not every program works this way. I just tested it out on OSX and it failed to respond to anything but 127.0.0.1. In contrast, Ubuntu reponds to anything within that 127.* block. I would expect Debian and most other distros to act the same way (barring a firewall rule blocking ping requests).

As for ping, as goku mentioned, 127 is 0x7f in hex (only the first bit isn't set in that byte. I don't know exactly why the .1 part is assigned to the end, other than to say that's the way its programmed. You should get the same results as typing in "ping localhost."

A borderline amusing usage of hex addressing but it's only point is to obfustcate things. For future reference, 0x is the common prefix to indicate that you're looking at a hexadecimal number. Another common base is octal, and is indicated with a leading 0. This is even less well known, leading to the confusing command

ssh 0177.1

A box which suspiciously has the same password as yours!

Justin

adding .1 just makes it work. Weird though. Seems like 127.1.*.* are all able to be pinged and get a response from 127.0.0.1.