"Conflicting" IP addresses on a server after a reboot; DNS shows no conflicts
Posted on 2013-02-07
We have a server running Windows 2008 SP2 that is our front-end to our SharePoint site. No changes have been made to it in nearly a year.
For the past several months, the system will reboot cleanly and be available through the terminal, but after rebooting no one can access the server at the primary IP (10.0.0.24), though the secondary (.23) was accessible. I changed the primary NIC to .22 for testing purposes, and it came up right away. When I attempted to re-assign .24 as primary, it failed due to a duplicate IP address being detected. I'm unable to ping or find any other trace of another device on .24, but the SharePoint server is insisting that there's a conflict when I try to re-assign that address.
That being as it is, I changed the primary IP of SharePoint to 10.0.0.22 - changes have been made in DNS, and we updated the firewall rules for this change as well. Everything works fine until...
The server is restarted a month later and the same process is followed; except that the server complains that .22 is in use -- so we have to choose another IP... ad nauseum.