So today I was working at a site that has a single Exchange 2010 server that forfills all the Exchange roles (I know….) which happened to fall on its ass.
First thing I did was check the Exchnage services which were in a state of “starting” which is never good and then I went to the registry and found:
MSExchange ADAccess, EventID 2141
Process STORE.EXE (PID=2996). Topology discovery failed, error 0x8007077f
MSExchange ADAccess, EventID 2142
Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1760). Topology discovery failed, error 0x8007077f
Here’s a few screen shots:
As well as a few more related to AD.
After some investigation I found out that a new DC in a new site had been created for some DFS replication amongst other things.
So next up is to look at Active Directory Sites and Services:
And as you can see from the screen shot the subnets are missing, which is going to cause issues as the new DC is on a different subnet.
When Exchange can’t determine in which site a computer belongs, the function DSGetSiteName, used to retrieve the current site, returns an error 1919 0x77f (ERROR_NO_SITENAME) which in turn kills off Exchange. You can test this by running nltest /dsgetsite in a command prompt or by having a look at HKLM\System\CurrentControlSet\Services\Netlogon\Parameters\DynamicSiteName.
To solve the issue you can do any of the following:
- Making the site association static using a registry key, which isn’t a best practice. If you must, set registry key HKLM\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters\SiteName(REG_SZ) to the desired site name;
- Adding proper subnet definitions;
- Remove the new site.
Finally give Exchange a bounce and BOOM.