I’m in the process of deploying a couple new Server 2008 R2 domain controllers. I’m using two IBM blades, each having a pair of Broadcom NICs that I configured in fault-tolerance teams.
In trying to verify the configuration of one of the DCs, I used the command:
The output surprised me:
Starting test: Connectivity Message 0x621 not found. Got error while checking LDAP and RPC connectivity. Please check your firewall settings. ......................... CDC01 failed test Connectivity
I ran the command from a Server 2008 Sp2 (not R2) host:
dcdiag /s:cdc01 /test:dns
The test passed without error. Strange. I verified firewall and DNS. Then turned to the hivemind. This post shows similar behavior. This post on the TechNet forums identified the NIC Team as a probable source, and a contributor referenced a hotfix KB978387 for a bug in dcdiag on Server 2008 R2 on systems with NIC Teams.
Installed and now the test passes:
Starting test: Connectivity ......................... CDC01 passed test Connectivity
I spent much of my day working on this, and on tracking the connections to AD by clients using unsigned SASL binds or LDAP simple binds without an encrypted connection.