Can't ping Windows Server 2008(different subnet) until ARP cache is cleared

**andygps** · 18-10-2011

We currently have XP workstations, some 2003 servers, and some 2008 R2. All are currently on 10.2.19.x. This pool has been filled so we are trying to add some client PC's to 10.2.18.x(with subnet 255.255.254.0).
The problem is this:
Once I change the ip config on the XP workstation to 10.2.18.x as mentioned above, I no longer have access to servers running 2008, who are on the 10.2.19.x network. I still have connection to 2003 servers, just not the 2008. I have to manually delete the server's ARP entry on the client PC and the connection gets restored.
I checked the ARP tables before clearing and after successful ping, and the entries are the same. I tried manually adding an arp entry but that didn't work; i still have to clear the arp cache to restore connection.
Anybody have an idea about what might be going on?

**JAMES_911** · 18-10-2011

Does this sound like the problem you are having?

http://blogs.technet.com/networking/...cast-mode.aspx

**andygps** · 18-10-2011

Originally Posted by james_911

Does this sound like the problem you are having?

http://blogs.technet.com/networking/...cast-mode.aspx

Thanks for your reply, I had seen that while looking for a solution, but no, we don't have NLB installed. Also, there is no connection problem with the default gateway at any point, just with servers running windows server 2008.