Hostname funniness

[Dmitriy Kropivnitskiy]

On Thu, 2004-11-18 at 18:11 +0000, Adam D. Barratt wrote:
> 127/8 is localnet. If you `sudo ifconfig lo', you'll find that interface
> is listening to the whole /8, not just 127.0.0.1 (i.e. it has a mask of
> 255.0.0.0).

Netmask of 255.0.0.0 doesn't mean that an interface listens on the whole
A class, just means that only the first 8 bits of the address is the
network number and the rest is the host number. In this case the host
number is 1 and network number is 127. For example if your eth0
interface has address 192.168.0.1 and netmask 255.255.255.0 it is not
going to listen on the whole /24 but only on the .1 address. So, I
suppose there is some magic in the lo interface making it answer on any
address from 127. A class. I will go read RFCs now.