Situation: I transferred fsmo roles from 2012r2 to 2016, everything checked out, network was fine for a few days. I demoted the former dc and the issues came.
Summary: nltest gives errors that no such domain or cannot be contacted.
dcdiag:
Running enterprise tests on : us.domain.com
Starting test: LocatorCheck
Warning: DcGetDcName(GC_SERVER_REQUIRED) call failed, error 1355
A Global Catalog Server could not be located - All GC's are down.
Warning: DcGetDcName(TIME_SERVER) call failed, error 1355
A Time Server could not be located.
The server holding the PDC role is down.
Warning: DcGetDcName(GOOD_TIME_SERVER_PREFERRED) call failed, error 13
A Good Time Server could not be located.
Warning: DcGetDcName(KDC_REQUIRED) call failed, error 1355
A KDC could not be located - All the KDCs are down.
......................... us.domain.com failed test LocatorCheck
nslookup
Server: localhost
Address: 127.0.0.1
priority = 0
weight = 100
port = 389
svr hostname = dc1.us.domain.com
dc1.us.domain.com internet address = 10.24.16.10
>
Netdom query failed: the specified domain doesn't exist, or cannot be contacted.
rep admin /replsum
Source DSA largest delta fails/total %% error
OLDDC 01d.00h:46m:20s 10 / 10 100 (5) Access is denied.
DC1 01d.00h:31m:17s 5 / 5 100 (5) Access is denied.
Destination DSA largest delta fails/total %% error
DC1 01d.00h:34m:42s 5 / 5 100 (2148074274) The target principal name is incorrect.
DC3 01d.00h:46m:21s 10 / 10 100 (5) Access is denied.
Experienced the following operational errors trying to retrieve replication information:
8341 - olddc.us.domain.com
1326 - dc2.us.domain.com
58 - 24ccb0b8-dab4-4730-acff-1ee490af6fc5._msdcs.us.domain.com