@Obsolesce said in DNS Update Issue:
@scottalanmiller said in DNS Update Issue:
@PhlipElder said in DNS Update Issue:
@Donahue said in DNS Update Issue:
@scottalanmiller said in DNS Update Issue:
@Donahue said in DNS Update Issue:
right, but I wonder if my branch DC should be pointing to the HQ DC, or just going straight to external?
Branch DC's DNS should point first to the loopback, then to the HQ DNS. That way to minimize WAN traffic, and maximize performance.
in the NIC settings, correct? Should HQ secondarily point to branch?
ADDS DCs with integrated DNS should have only one DNS entry on the NIC: DNS0: Own IP
When a DC is elevated it drops the loopback address in.
Again, an AD integrated DNS server does not need any other DNS servers assigned to its own NIC. That's taken care of by AD and DNS replication.
But the whole question is what happens when the DNS fails locally.
When does this even happen? How do you have a DC/DNS server running, then suddenly the DNS service breaks? Then what? Just fix it and be done with it. Restore the zone, whatever... if it's the only DC, a simple restore will get you up and going in 10 minutes. If there's others, and DNS is corrupt, it'll replicate and corrupt the other DNS servers too. AD integrated DNS zones replicate.
If the DNS role/service fails on a DC, you have bigger issues. If it's corruption or deletion, well all your other ones will be screwed too anyways.
The only time we've hit this is in a full power outage situation where there was not enough UPS to keep things up and running.
With Cloud Witness there needs to be a DNS server alive prior to the cluster nodes firing to allow them to find that cloud located witness or no-go for starting the cluster.
For on-premises, if DNS is offline there's more going on there than a simple oops. What we do while recovering the DC if it's going to take longer than 15-30 minutes is flip DHCP Services on at the edge and have the clients release and renew their IP address to pick that up. Then, at least they are somewhat productive while we're working on the recovery.
As soon as the DC is back online DHCP gets turned off at the edge and the clients renew their IP address to catch the DC again. Done.