We're having a really odd problem with some test Vista Business machines on our network, which has 2 Windows Server 2003 DCs and several member servers.The Vista machines have a standard build on them, and can't initiate any communication with the DCs - ping, browsing, accessing printers all fail. However, if we initiate communication from the DCs to the Vista machines first (via a ping), they can respond and access the servers. This meant we couldn't get them to join the domain intially, but but ping continuously from the DC, we could get them to join. However, you can't log in properly with a domain account either.We can't see anything odd on either the DCs or the Vista machines. The Vista machines can ping other clients and ping and browse to all the member servers, just not the DCs. XP machines and access everything fine. My thoughts are this is something to do with group policy or local policies trying to encrypt communication between the Vista machines and DCs but can't find anything in either domain or local policies causing this.Anyone got any ideas?Thanks

Joe, did you ever receive a response to this post? We are seeing the same issue. Thanks, heath

Does anyone have an answer to this? We are having the same issue. We did just find it had something to do with the NIC. We are using a blade with two NICs and the other was disabled. We enabled it, gave it a different IP and were able to ping that IP. We then disabled the original NIC and gave the other NIC the original IP and this worked. Still not sure what the original problem was but this works. Also, we did get a temporary fix for one ping earlier by running this command on the server: netsh interface ip delete arpcache.