Hello All,
I have a network that was upgrading their Exchange to the latest CU 15. During the upgrade the process stopped around 98%. They rebooted the servers(Exchange 2016, PDC running CA and a secondary DC running DNS) and when they came back up there were major
issues. The first and foremost is(I think) an RPC error 1722 between the PDC and the secondary DC. I have run all the dcdiag tests along with dtcping and each shows the RPC error 1722. This is where it gets interesting. Most of the tests will come back that
they have passed(except for the 1722 error). After digging into the system for the day I found that the security settings for the secondary as well as the primary DNS servers are showing SIDs for about half of their accounts. The on site Enterprise CA
is not working with RPC server unavailable errors. The on-premise Exchange 2016 server will not boot due to this issue either. Under Server manager when trying to access the other DC I receive"target not accessible" error message. There are DCOM
10028 errors about connecting to the other servers(unable to communicate using any of the configured protocols). It looks like the DC1(which is the PDC-Em) holds the RID/PDC/Infra roles(according to itself) when looked at from the ADU&C snap-in. On DC2
it shows unknown for each.
1: the last event viewer entries show DC 1&2 that Active directory Web Service is servicing the directory instance as GC, LDAP & SSL.
2: DFSR is showing 1727 on each DC. It reported that the last time it worked was about noon today.
3: Port Query shows port 135 (epmap) listening on both servers. It lists 120+ endpoints for each server.
4: DNS was/is signed. I can remove from DC1 dns and reapply, but not from DC2(I tried to remove and transfer the Key Master role to no avail.
5: I have tried to reset the machine and user account passwords.
What am I missing???
Devin