I'm using a Mikrotik RB951G-2HnD (RouterOS 6.35) with dual WAN links for failover.
It's configured with:
- primary PPPoE interface, Default Route Distance = 1
- secondary PPPoE interface, Default Route Distance = 2
- Use Peer DNS enabled on each PPPoE interface
- Both interfaces are active/enabled all the time

In the event the primary fails e.g. fibre outage:
- the default route will fail over to the secondary
- the secondary Peer DNS will be used

When the primary is restored:
- the default route will revert back to the primary
But what happens to the Peer DNS? Do they revert to the primary Peer DNS?

Looking at the DNS Settings (in Winbox) the secondary Peer DNS will show as Dynamic Servers 1 & 2, the primary Peer DNS will show as Dynamic Servers 3 & 4.
This suggests that DNS does not revert to the primary Peer DNS.
This causes problems as secondary Peer DNS are not accessible from primary.
Changing to static DNS e.g. Google DNS is not an option.

Bump - any info on how the Peer DNS are handled?