DHCP 'weirdness'

[Reuben D. Budiardja]

Hi all
On our campus here the default is that machine will get their IP from DHCP. I 
have one machine that we use for our development and mail server. For the 
last two years, the machine has the same IP, even after rebooting and 
restarting network connection. It's running RH 7.3.

Now I tried to install RHEL 3 on the machine by adding a second HD, so I don't 
destroy the previous install; in case something bad happen, I can just switch 
the HD and boot the original Redhat 7.3.

After installing RHEL 3 and set up to boot from DHCP, I notice something kinda 
weird. Everytime I reboot, or restart network connection, I would get a new 
IP. I know in principle, that's what DHCP does, but why does not this happen 
with my previous RH 7.3 install? It's an annoyance especially since if you 
SSH to the machine from other machine, SSH would complain (something about 
know_host entry does not match, you all know what I'm talking about when 
machine changing IP). 

The funny thing, I put in the original HD, and boot the original RH 7.3, and I 
got the same IP back that I've had for the last two years. what gives? ? I 
checked and made sure that both RH 7.3 and RHEL 3 boot from DHCP. So any 
suggestion on how to "trick" the DHCP server so I can get my old IP, always ? 
or at least retain the new IP so that it does not keep changing after reboot. 
(I don't have any control over the DHCP server, and when I tried forcing 
static IP on the machine, the DNS is not set correctly, ie. if I do 'host 
<ip>' I would get host unknown).



Thanks for any help.
RDB

-- 
Reuben D. Budiardja
Department of Physics and Astronomy
The University of Tennessee, Knoxville, TN
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