MSExchange ADAccess 2080

Question

Hi All,
We have two Exchange 2013 servers set up in DAG with 2 DC's running in a single site. We had to reboot DC1 and before it came backup MAIL1 then crashed and rebooted.
Checking out the logs before the crash I can see that when DC1 was rebooted MAIL1 was unable to locate another DC in the site, even though there are two.
Checking the MSExchange ADAccess errors when DC1 was back online, MAIL1 is only reporting the following:
Process Microsoft.Exchange.Directory.TopologyService.exe (PID=64668). Exchange Active Directory Provider has discovered the following servers with the following characteristics:      
 (Server name | Roles | Enabled | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version)      
In-site:
DC1.domain.com CDG 1 7 7 1 0 1 1 7 1  
Where as MAIL2 remained online and reports:
Process Microsoft.Exchange.Directory.TopologyService.exe (PID=164764). Exchange Active Directory Provider has discovered the following servers with the following characteristics:      
 (Server name | Roles | Enabled | Reachability | Synchronized | GC capable | PDC | SACL right | Critical Data | Netlogon | OS Version)      
In-site:
DC1.domain.com CDG 1 7 7 1 0 1 1 7 1
DC2.domain.com CDG 1 7 7 1 0 1 1 7 1 
All services etc failed over using DAG when MAIL1 went offline so this side isn't an issue but i'm trying to locate why MAIL1 is only reporting seeing DC1 and not DC2.
Thanks.

Answer 1

Hi,
I agree with Nagendra, you should run dcdiag on DC2 and check the result.
Beside run dcdiag , I also recommend you check the DNS SRV record, or try to reboot dc2 and check if ok.
Thanks.
Niko Cheng
TechNet Community Support