I recently reconfigured some CentOS 4.3 systems that were using DHCP to use static IP addresses. At the same time, the systems were moved to a new VLAN. Here is the approximate sequence of events that took place:
1. ifdown eth0 2. edit /etc/sysconfig/network-scripts/ifcfg-eth0 with static IP address 3. wait for network folks to reconfigure switch 4. ifup eth0
I may have reversed steps 1 and 2 on some of the systems.
The problem was that the dhclient process didn't go away, and kept renewing the old lease. Our DHCP server is configured to contact the DNS server and update the entry for each host it serves. So the DNS entries for these systems were pointing to the old address in the old VLAN. The eth0 interface itself just kept the static IP address for which it was configured. It took me a while to figure out what was going on.
My question is, what could I have done to avoid this (other than killing the dhclient process)? Is there a better way to reconfigure an interface to use a static address? I am not interested in solutions that involve using a GUI (i.e., only command line solutions).
Thanks, Alfred