I am not sure what category to post this in, as it may relate to multiple network devices, but I will try here first.
We are a small co (roughly 300 users) operating under a much larger umbrella co. Our larger co. recently upgraded to AD, forcing us to do the same (From good old NT4).
All of our clients run XP and DHCP, and we use all Cisco routers & switches. Locally here in IL we have 10 sites, all connected via WAN and all authenticate to our AD controller locally, and that same box runs DHCP for all the clients. The primary DNS boxes are at our corp office, and it just pushes down all the DNS to our local controller.
Implementation went pretty smooth, and shortly thereafter we start getting a lot of calls about people not being able to get into many critical applications. We realized all the XP clients had their firewalls reactivated. So we set up policy to turn all of those off. Then we began getting calls about critical web sites not being able to function. After looking closer at our XP clients, we noticed the clients had pulled all the new DHCP info, but were also retaining as a primary an old DNS box that no longer exists. We double and triple checked our DHCP box, and it is and has been configured perfectly for all our sites. We reset all our routers and switches, and had everyone restart their machines. This did not fix anything. The only "quick fix" is to do an "arp clear" locally and then "ipconfig/renew". This fixed the issues for some time, and then they get the wrong info right away.
This is starting to become a daily annoyance and has been driving our help desk insane for the past week since AD was rolled out.
We have also restarted DNS services, and cleared ARP on the server as well.
Anyone have any ideas why this could be happening? Keep in mind there are over 20 other sites like ours connecting to our corporate office, and we are the only ones having these issues, which makes it that much more frustrating.
Any help would be appreciated.