After some changes in my Active directory (Win. 2003 R2) the Exchange 2003 SP2 does not work correctly. I install a new Windows 2008 as Replication server of my old Windows 2003 active Directory. After this my exchange server does not work correctly. for resolving this problem I demote win.2008 Rep. server again, so I returned to previous configuration(Server 1: windows 2003 r2 DC , Server 2 : Exchange 2003 with Win 2003 R2). Unfortunately after this roll back still exchange server does not work. Now the exchange periodically down every 1 hours and after 10 to 15 minutes automatically up again. When the server is down the following error occurred: MSExchangeAL LDAP Operations 8026 LDAP Bind was unsuccessful on directory DC.samansat.com for distinguished name ''. Directory returned error:[0x51] Server Down. ****************** Error 2: MSExchangeSA 9154 DSACCESS returned an error '0x80004005' on DS notification. Microsoft Exchange System Attendant will re-set DS notification later. ************************* Error 3 : MSExchangeDSAccess 2102 Process MAD.EXE (PID=3792). All Domain Controller Servers in use are not responding: DC.samansat.com I follow these article in Microsoft website, all thing is correct. support.microsoft.com/kb/319065, support.microsoft.com/kb/246127, support.microsoft.com/kb/254030 It seems the LDAP port 389 is closed in exchange, for solving this problem I disable Firewall in DC and Exchange. During a problem time outlook client request Domain username and Password. Please help me about this problem.

Hello, Please run dcdiag to check if DC works well. Please run netdiag to check if the network works well. Here are some article on these errors for your reference. http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.6940.0&EvtID=8026&EvtSrc=MSExchangeAL http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.0000.0&EvtID=9154&EvtSrc=MSExchangeSA http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.6940.0&EvtID=2102&EvtSrc=MSExchangeDSAccess Cara Chen TechNet Community Support

Is it possible some data or metadata from Win. 2008 (Installed Replication Server) remains in Exchange or DC settings? (For example is It possible Kerberos tickets that are associated with the LDAP are requested from Win. 2008 which now are demoted?)

Hello, The issue may occur when exchange can't contact to DC. Please as my suggestion to check if your configuration is correct. Cara Chen TechNet Community Support

All test in DCDIAG command is passed except the following test failed message: ......................... DC passed test frsevent Starting test: kccevent ......................... DC passed test kccevent Starting test: systemlog An Error Event occured. EventID: 0x00000457 Time Generated: 10/13/2012 16:14:49 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 10/13/2012 16:14:50 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 10/13/2012 16:38:46 (Event String could not be retrieved) An Error Event occured. EventID: 0x00000457 Time Generated: 10/13/2012 16:38:47 (Event String could not be retrieved) ......................... DC failed test systemlog Starting test: VerifyReferences ......................... DC passed test VerifyReferences Also in NETDIAG command the following message appear to me: DC list test . . . . . . . . . . . : Failed 'MyDomain': No DCs are up. Trust relationship test. . . . . . : Failed 'MyDomain': No DCs are up (Cannot run test). [FATAL] Secure channel to domain 'MyDomain' is broken. [ERROR_NO_LOGON_SERVE RS] Kerberos test. . . . . . . . . . . : Passed LDAP test. . . . . . . . . . . . . : Passed [WARNING] Failed to query SPN registration on DC 'DC.MyDomain.com'.