We suddenly have outlook XP clients unable to connect to our exchange 2007 server.
The client tries then pops up the server not available message asking to try again or work offline. I confirmed the client can ping and browse to the server.
Trying to compare the same user logged into 2 computers in the same room with the same network settings can get in on one but not the other. The users can also log in to OWA fine.
The issue occured after a server reboot which installed about 10 updates to server 2008. I'd prefer to fix the clients rather than start uninstalling updates to the server.
There seems to be no specific update or setup different in the computers that work vs those that don't. Reinstalling office XP does not resolve the issue but upgrading to office 2003 client does. We just do not currently have the licenses to upgrade all the clients.
For us the issue was a change that our network team was in the process of making that I was unaware of. They were starting to add an additional Internet Provider and to do so began splitting traffic by odd/even IPs as a way to load balance between the two. We were tipped off when during our troubleshooting of the clients we noticed it was the older version of outlook but only the even number IP's that were having the issue.
We don't know why this effected only the older version of outlook but once the network side added proper routing tables the issue went away. It appeared that the older version of outlook with the even IP's was trying to go outside the network to look for our exchange server instead of properly routing internally.
Hope that helps
We are having the same issue as well, and it's only on the older Outlook XP clients that are having problems. clients that have DHCP'd an IP address that is odd is able to connect to the Exchange Server, those that DHCP an even IP cannot. I added static IP address to the PC and still had the same issues, Even's failed, Odd IP's connected. I skipped around IP addresses alot just to make sure it wasn't because it was every other connection, it had everything to do with whether it was an even or an odd IP. We only have one network route out, and the PC and server are on the same LAN, so the connection should never go though a router. even when on an even IP I can ping the server, and NSLookup of the server is also sucessful. A Tracert to the server shows a direct (0 Hop) connection whether it was working or not.
As further information, even when Outlook XP is installed on Windows 7 OS, it still has the same connectivity issues, if it has an even numbered IP. However, upgrading to the Outlook 2003 client seems to have solved the issue for us, since we were only keeping the older Outlook clients for Outlook routing. Outlook 2003 still allows the Outlook routing function, and fixes the connectivity issue for us.