Problem: Â One afternoon, my users could not access their Exchange email through outlook or OWA. Â No changes have been made and the server was up and running but no one could access it. Â I couldn’t even access it when on the Exchange server itself. Â I checked the logs and saw the following errors:
Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=2060). Topology discovery failed, error 0x8007077f.v
Unhandled Exception “The Microsoft Exchange Active Directory Topology service on server localhost did not return any suitable domain controllers.”
Stack trace: at Microsoft.Exchange.Data.Directory.DSAccessTopologyProvider.GetConfigDCInfo(Boolean throwOnFailure)
Solution: Â After some research, I realized that indeed my Exchange server could not find a domain controller, even though they were both on the same subnet. Â Â This issue had to do with a change I made earlier in Active Directory Sites and Services where I created a new subnet for a remote site and assigned the domain controller located on the site to the “Default-First-Site-Name” for that subnet. Â The issue was that I forgot to create a subnet where the other DC’s were located and the Exchange server… Therefore, the Exchange Server had no DC to authenticate to. Â What I did was then create a new subnet (of the original DC’s and Exchange server) and set the DC’s there to theÂ Default-First-Site-Name for that subnet. Â Once all of my DC’s replicated I rebooted the Exchange Server and all was functioning well.