I've got a general question about SRV records under _msdcs. Specifically, in _tcp.<GUID>.domains._msdcs.
We have 21 Domain Controllers (All Server 2012 R2) in our Domain and all of them are configured as Global Catalogs and all of them are configured to register their connection addresses in DNS.
But, in _tcp.<GUID>.domains._msdcs.<parent domain>.Forward Lookup Zones, only 8 of those DCs are showing up.
The same 8 show up in _tcp.gc._msdcs.<parent domain>.Forward Lookup Zones, but not the other 13 DCs in the Domain.
Ditto for _tcp.dc._msdcs.<parent domain>.Forward Lookup Zones, _tcp.<parent domain>.Forward Lookup Zones and _udp.<parent domain>.Forward Lookup Zones.
This isn't causing any trouble for us, but it would be nice to know the reason why SRV records for all 21 DCs are not recorded in these containers and only 8 of them specifically are.
BTW, all 21 do show up in _sites.<parent domain>. Forward Lookup Zones.