I was wondering if anyone had seen and fixed this one:
We have a number of Windows 2003 SP2 based DCs which normally work well. However, sometimes after a warm reboot they fail to correctly initialise their network connections - the cards are enabled and appear to be working correctly but traffic does not flow over the cards. This is the case on both their LAN and iSCSI interfaces.
A subsequent warm reboot fixes the issue (e.g. they start up normally and work fine). Cold Reboots do not appear to cause the problem. We've seen this issue with different hardware, both in terms of the server platform (different models of Dell PowerEdge) and different network cards (broadcom & Intel based NICs). And of course we've tried different versions of drivers for all the network cards we have tried.
There are no windows or 3rd party firewalls running on the servers.
Just a shot in the dark here, but what do your switches say is going on? Do you see any entries about the port being shutdown because of attempted mac spoofing or other security issues? Are the MAC addresses in the MAC table after the first (non-working) reboot?
This smells more like a switching problem then a server/host problem.