DNS issues quad9 etc

General
1

I am having some weird issues with DNS resolution. Perhaps I am doing something wrong?

Network > Untagged VLAN > if I assign DNS server here of 9.9.9.9 I see 9.9.9.9 show on the client ipconfig, for example ipconfig /all, I see 9.9.9.9 listed as DNS server. I cannot resolve anything on the clients. If I change to 8.8.8.8 I can resolve and there are no issues.

If I instead set that to “Assign DNS server automatically” and go to Network > WAN > DNS over HTTPs > Enable and set to Quad9 from the dropdown, then I go to ipconfig /all, I see the Peplink IP 192.168.1.2 listed as DNS, everything seems to work and going to https://on.quad9.net/ verifies quad9 is in use.

ISP is adamant they are not blocking 9.9.9.9 but methinks there is something going on with DNS setting somewhere. I tried 1.1.1.2 which is Cloudfare and I had same issue as Quad9.

Anyone have any ideas?

Also, when I select Network > WAN > DNS over HTTPs > Enable and set to Quad9, what is the secondary DNS server being used or is it possible to set a secondary in case 9.9.9.9 goes down?

2
  • Have you reviewed the firewall rules?
  • Have you reviewed the Application Blocking options?
  • Have you reviewed Advanced > Service Forwarding > DNS Forwarding Setup?
  • On the client, have you tried anything like nslookup to query a specific name server regardless of the configuration received with DHCP?