Hello, I hope someone can assist us. We recently performed 2 upgrades to our system which was running fine prior to these upgrades. We applied Exchange 2003 SP2, and on our new proxy server, we applied Server 2003 SP2. We also went from ISA 2000 to ISA 2006. We paid a company to do this and it has been nothing but a mightmare since then. We are seeing that our proxy server is not allowing anyone to remote desktop into it (which worked before), on our Exchange server we see the following event IDs in the event viewer (2102, 8026, 9153, and 8213). On our proxy server we are seeing the following event IDs( 21265, 11165), and lastly we are seeing on our backup domain controller an event ID of 8003. Our network has become completely unstable and as of now, I cannot even remote into our network. Our website is down as well (we host our own). We are also seeing that our Exchange server keeps messages in the outgoing queue for hours before it flushes them out. When we left on Saturday with only 1 person on the network, we were seeing a lot of network traffic on all our switches. During my research of this problem, I did see I need to verify our subnet masks, I also think I need to make sure that we are in native mode on our exchange as we only have the one Exchange server which is running Exchange 2003 SP2. Our "expert" had Microsoft support on the phone twice and I have no idea what they did to our system. I am going in early tomorrow morning to work on getting our network up. Does anyone have any ideas?

Update - Subnets were configured fine, we are not in native mode as SRS is installed. According to the Microsoft article on how to switch to native mode, SRS needs to be uninstalled. I am not yet prepared to do this at this time, we are having enough issues. Some of the errors from event viewer we are getting today are: 1 (This error is occuring multiple times per minute): Event Type:ErrorEvent Source:MSExchangeALEvent Category:LDAP Operations Event ID:8026Date:12/26/2007Time:11:59:17 AMUser:N/AComputer:CTMAILDescription:LDAP Bind was unsuccessful on directory nudomsvr.magnum.magnum-corp.com for distinguished name ''. Directory returned error:[0x51] Server Down. DC=magnum,DC=magnum-corp,DC=com For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 2: (This error is occasional): Event Type:ErrorEvent Source:MSExchangeDSAccessEvent Category:Topology Event ID:2114Date:12/26/2007Time:11:58:08 AMUser:N/AComputer:CTMAILDescription:Process STORE.EXE (PID=3888). Topology Discovery failed, error 0xffffffff. For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 3new message, I am not thinking this is a critical error) Event Type:ErrorEvent Source:MSExchangeTransportEvent Category:Exchange Store Driver Event ID:348Date:12/26/2007Time:11:53:59 AMUser:N/AComputer:CTMAILDescription:A message could not be virus scanned - this operation will be retried later. Internet Message ID <e717c90c8b7b4a5e912be8a05edd87ad@eb.emediaUSA.com>, Error Code 0x0. For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 4The prerequisite domain controller errors): Event Type:ErrorEvent Source:MSExchangeDSAccessEvent Category:Topology Event ID:2102Date:12/26/2007Time:11:53:39 AMUser:N/AComputer:CTMAILDescription:Process MAD.EXE (PID=3160). All Domain Controller Servers in use are not responding: nudomsvr.magnum.magnum-corp.com apsmrp.magnum.magnum-corp.com For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. 5: (This is a new message): Event Type:ErrorEvent Source:MSExchangeIS Mailbox StoreEvent Category:General Event ID:7200Date:12/26/2007Time:11:48:00 AMUser:N/AComputer:CTMAILDescription:Background thread FDoUpdateCatalog halted on database "First Storage Group\Mailbox Store (CTMAIL)" due to error code 0x80004005. For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. (these 2 seem to be related) Event Type:ErrorEvent Source:MSExchangeIS Public StoreEvent Category:General Event ID:7200Date:12/26/2007Time:11:48:00 AMUser:N/AComputer:CTMAILDescription:Background thread FDoUpdateCatalog halted on database "First Storage Group\Public Folder Store (CTMAIL)" due to error code 0x80004005. For more information, click http://www.microsoft.com/contentredirect.asp. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. A reboot on this server this morning helped for about 2 hours, then we are right back where we started. Do these help any?

We did some DNS cleanup and we are now running very stable.