Hi got an AD with roughly 20 servers in. Had a DFS root running no problems on 2008 server with no problems. All clients, 300 odd, and the rest of the servers happily access it. Recently upgraded main file server to 2008 R2 from 2008, and this server struggles like mad to get to the dfs share from either unc or mapped drives. 90% of the time it'll time out with no available, sometimes it'll go the root, see the shares below and won't go in any of them whereas othertimes it'll go into the subdir's but not all. S:\ is not accessible the specifiied network name is no longer available \\FQDN\root share -- hangs with network name cannot be found (just about to look at this more 0x80070043) \\FQDN\sysvol or \netlogon is fine just seems to be the DFS share but no other client or server is doing this Nothing gets logged in the event view, IP/WINS/DNS all look the same as before the upgrade. Any clues to where I could look Regards Matt

Update it can no longer access via UNC any share on the server, regularly, I just saw it drop the connection as I went to cd a dir if I use \\IP\sharename it appears to be fine unless I go for \\IP\DFSRoot

Maybe try the suggestions from this article http://support.microsoft.com/kb/983620 in particular the dfsutil /pktflush command. Let me know how you go as I have the same problem which I fix by rebooting though it hasn't happened in a while. If it does happen again I'll probably try the hotfix or that dfsutil command.