Our team is migrating around 2x SBS 2003 servers as week right now over to SBS 2011 Standard. We’ve gotten pretty darned good at it but every now and then something stops you dead in your tracks. Today one of the guys was onsite doing part of the preflight check on a migration. As part of that we need to revert the server from a 2 NIC configuration with ISA as the firewall to a single NIC configuration. He did this and rebooted the server as planned. However after the reboot we found that there were issues. Users could not do DNS, they could not get an IP via DHCP or anything like that at all. After scratching our heads for a bit we finally remembered something we long forgot now… the Scalable Network Pack that Microsoft deployed as part of Windows Server 2003 SP2 was the problem. It’s been at least 5 years since I’ve seen an issue caused by this and for some reason the patch that Microsoft released to disable these features on SBS was not applied to this server. The patch I’m talking about is this one http://support.microsoft.com/kb/948496. After we applied this and rebooted – everything was fine.
I’ve got to say though… it’s been a while since I’ve seen this issue. You can bet that a check for this patch is now part of our server build/migration documentation for sure!