[luau] dhcp-146-41

[Ray Strode]

> I noticed that, instead of the usual "localhost", the computer was 
> designated, out of the blue, a name called "dhcp-146-41".  It was 
> subsequently concluded that this was the source of all the problems 
> (including inability to install printer driver, etc.)
>
Not sure why it's causing so many problems, but I can explain a little 
bit about how the process works on
redhat.

First, the computer requests an ip from the dhcp server (called DHCP 
request), then
dhcp server returns the computer's ip address and other network 
information, including the dns server
(called DHCP ACK [ACK is for acknowledgment]).  Some time during this 
process the file
/etc/sysconfig/network gets sourced and certain environment variables 
are set.  

If HOSTNAME is one of the environment variables to get set and it is set 
to something other than
"" or "localhost", then the hostname of the system is set to $HOSTNAME.

If HOSTNAME is not set, or it is set to "" or "localhost"  then the 
computer performs a reverse lookup on the ip
it was just given (by asking the dns server it was just told about). 
 Whatever results from this reverse lookup is the
hostname assigned to the system.  If the reverse lookup fails, then the 
hostname is set to localhost.  
--Ray