Hello @gjr ,
the first one is not a true issue 127.0.0.1 cannot be used as a DNS server as it is the local loopback in TCP/IP stack.
The second one looks like more serious:
>> kernel: [ 1845.205993] ICMPv6: RA: ndisc_router_discovery failed to add default route
If you are using IPv6 and IPv6 routing this can have an impact as it tells that the neighbor discovery process of ICMPv6 was not able to add a default route that likely is present in a received router advertisement RA likely from provider router.
If you are not using IPv6 you can ignore the second message too.
Hope to help
Giuseppe
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