Hi,
I have an Exchange 2013 environment that I'm trying to migrate to from an existing 2007 environment in the same domain in the same forest. I'm proxying all EAS, OA, and EWS traffic through my Exchange 2013 environment. I have 2 CAS/FE servers that only have the CAS role on them in an NLB, which is where this traffic is directed to. It seems these then proxy through an Exchange 2013 mailbox server, which then proxies to Exchange 2007. This broke yesterday.
Let me start by saying this was working fine for almost two months, but after rebooting all the Exchange 2013 mailbox servers in my environment, it broke. I'm looking for things that could have potentially broke. The reboots were due to 2 changes. I changed a cert that was installed on the Exchange mailbox servers to match what else is in the rest of the environment (The TMG's, the 2013 CAS servers, the 2007 CAS servers all have this new cert now). It's a typical mail.domain.com cert, which
was already installed. The only thing that changed was that some SANs were added to that cert. The other change was giving a service account privs to the Exchange DB's: get-mailboxdatabase -IncludePreExchange2013 | Add-Adpermission -user {user}
-AccessRights "GenericAll"
The behavior I'm seeing is that connections are proxied through a single mailbox server no problem like usual and then that mailbox server suddenly refuses the connections. It's like some threshold is hit. It's just strange that it coincides with the reboots, but I'd imagine if those changes were the cause it would be broken all the time and not just 15 or 20 minutes after the server starts accepting proxy connections.
There is nothing in the App logs. In the HTTPERR logs I'm seeing connection drops, and I haven't made much headway sifting through the W3SVC logs. I haven't found anything yet though. Any ideas what to look at? Thanks.