IPv6 manual DNS

Routers
1

When I manually set IPv4 DNS server addresses everything works as expected, but when I manually set IPv6 DNS server addresses the router no longer resolves local (on the LAN) addresses. All requests get sent to the specified IPv6 DNS servers so all requests for local resources fail.

Am I supposed to specify IPv6 DNS addrs on the DNS panel rather than the IPv6 panel? If so, what does the router do with the DNS addrs entered on the IPv6 panel?

2

Hi

Yes, if you want local addresses like nas.lan to continue resolving correctly, please configure the IPv6 upstream DNS addresses under Network -> DNS.

Essentially, these are two different ways of handling DNS:

  • DNS specified in Network -> IPv6: This is delivered to clients via DHCPv6/RA. The clients will send DNS requests directly to the specified DNS servers, bypassing the router's DNS proxy. Therefore, DNS resolution for local addresses may fail.
    Client DNS request -> Google DNS (External)
  • DNS specified in Network -> DNS: These act as the upstream DNS for the router's own DNS server. Clients still use the router's LAN address as their DNS server. The router's DNS server can then distinguish whether a request is for a local addresses or needs to be forwarded to an upstream server.
    Client DNS request -> Router DNS server -> Google DNS (External)
                              | or 
                              --> Local resolution & return
5

I think it would be good to document that better. People familiar with other brands of routers (as I am) are likely to enter the IPv6 DSN server addresses on IPv6 panel (as I did). I then thought I had seriously damaged the configuration and did a factory reset.

Is there a situation where users would not want address resolution for local resources?

6

Thank you for your suggestion; we will discuss this with our product team.

Some users may have a standalone DNS server deployed within their internal network. In such cases, they prefer to have requests sent directly to the internal server rather than being proxied through the router, as the latter will causing the standalone DNS server cannot distinguish between specific LAN IP addresses.