I currently have IPv6 PD setup with Spectrum (FKA Charter) and I would like to use OpenDNS’ IPv6 DNS servers instead of the Charter’s. Maybe I’m just not quite understanding the CLI enough yet, but is this possible?
Not really, some have reported it working to set DHCP servers with regular DHCP in a dual stack method. Complain to MikroTik for their half-baked implementation like all of us have been doing as IPv6 continues to ramp up in relevance.
Now, to provide a more specific work-around. You can set your DNS forwarders to be OpenDNS and your clients can be told to use the MikroTik for DNS in IPv4. If you enable RDNSS you’ll find it only parrots the list in /ip dns avoiding the local caching resolver entirely. Another half-baked implementation.