I have 2 Exchange 2010 servers in a DAG. The witness server is in site A along with one the Exchange servers. The second Exchange server is in a DR site. The DAG has been functioning fine for 1.5 yrs. Last weekend after a scheduled reboot of all 3 servers involved (2 e-mail servers and the witness server), the e-mail server in the DR site cannot gain access to the witness share directory per the failover cluster manager. It says to check to see if the witness directory is on-line, etc... Using pings and explorer, there is no problem for the DR site e-mail server to contact the witness server and directory. Even restablished the Quorem to the same directory, no issues. Upon doing a network trace though, I am receiving KERBEROS pre-authentication errors when you start the Cluster service on the DR site e-mail server when it tries to contact the witness server:
(1.4 is the Witness server; 6.5 is the e-mail server in the DR site)
Source Destination
192.168.1.4","192.168.6.5","KRB5","319","KRB Error: KRB5KDC_ERR_PREAUTH_REQUIRED"
192.168.6.5","192.168.1.4","TCP","54","26049 > kerberos [FIN, ACK] Seq=235 Ack=266 Win=65792 Len=0"
192.168.6.5","192.168.1.4","TCP","66","26050 > kerberos [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1"
192.168.1.4","192.168.6.5","TCP","60","kerberos > 26049 [ACK] Seq=266 Ack=236 Win=66048 Len=0"
192.168.1.4","192.168.6.5","TCP","60","kerberos > 26049 [RST, ACK] Seq=266 Ack=236 Win=0 Len=0"
192.168.1.4","192.168.6.5","TCP","66","kerberos > 26050 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1406 WS=256 SACK_PERM=1"
192.168.6.5","192.168.1.4","TCP","54","26050 > kerberos [ACK] Seq=1 Ack=1 Win=66048 Len=0"
192.168.6.5","192.168.1.4","KRB5","368","AS-REQ"
192.168.1.4","192.168.6.5","KRB5","282","KRB Error: KRB5KDC_ERR_PREAUTH_FAILED"
192.168.6.5","192.168.1.4","TCP","54","26050 > kerberos [FIN, ACK] Seq=315 Ack=229 Win=65792 Len=0"
192.168.1.4","192.168.6.5","TCP","60","kerberos > 26050 [ACK] Seq=229 Ack=316 Win=66048 Len=0"
192.168.1.4","192.168.6.5","TCP","60","kerberos > 26050 [RST, ACK] Seq=229 Ack=316 Win=0 Len=0"
Thoughts anyone?