I have just linked three sites together(A, B & C) via a VPN to allow some basic file sharing and calandar sharing. Site A has a server running DHCP, exchange and file sharing. All was working ok, untill I changed ISPs, and now all I can do is ping each site across the network. I cannot connect to the exchanger server at all(which I am only using the calendar function), I cannot map any drives on the main file server, and I cannot add any of the external PCs to the domain and set up trusts. I have done troubleshooting and found this… - I can ping the server at location A via IP and its DNS name from all sites - All PCs at sites B & C have full internet connectivity when using the ISP’s DNS servers - If I add the servers details at location A the hosts file on PCs at B & C, I can ping, but still not able to map a drive, get exchange or add to domain - Same result if I add the server as the DNS on each PC Its got me stuffed, as it was working ok on the previous ISP, when using thier DNS servers, but now I cannot do anything besides PING, which indicates to me that its not a VPN problem, but more like some sort of DNS issues. Any ideas??

Why is this your issue? Put it back on the new ISP. Course it would have been a good idea to have documented from the former ISP what they did to make it work. If you have server 03 dns your pcs have to use it or no authenication. Your dns server will forward to the isps dns server(s). There is no getting around that if you want to authenicate to the server. Golly gee wilerkers everyone. Learn to Internet Search

It is on the new ISP, thats where the problem is. The previous ISP did not do anything to make it work, it just worked. Ill check the DNS forwarding on the server...

Ok, I am able to ping my DNS server, but nslookup fails, C:\Documents and Settings\peterc>nslookup *** Can't find server name for address 192.168.0.252: Non-existent domain *** Default servers are not available Default Server: UnKnown Address: 192.168.0.252 Any ideas???

I have done a bit more troubleshooting, and with a tracert I get this... tracert 192.168.2.254 Tracing route to 192.168.2.254 over a maximum of 30 hops 1 <1 ms <1 ms <1 ms 192.168.0.254 2 * * * Request timed out. 3 37 ms 39 ms 88 ms 192.168.2.254 Trace complete. Where is that middle hop going???