I've been thinking a little on the best way to handle this. For now I think removing the check against `ipv6_ra_conf` just asking for DNS whenever `ipv6_dnsenable` is set is the best thing to do, until Asus finishes whatever they're doing.

The [relevant section from RFC 6106](https://tools.ietf.org/html/rfc6106#section-1.2):

>  Two protocols exist to configure the DNS information on a host, the Router Advertisement options described in this document and the DHCPv6 options described in [RFC3646].  They can be used together. The rules governing the decision to use stateful configuration mechanisms are specified in [RFC4861].  Hosts conforming to this specification MUST extract DNS information from Router Advertisement messages, unless static DNS configuration has been specified by the user.  If there is DNS information available from multiple Router Advertisements and/or from DHCP, the host MUST maintain an ordered list of this information as specified in [Section 5.3.1].

Which just states to see [RFC4861] for deciding when to use stateless (RA) vs stateful (DHCPv6) for DNS. [Section 5.3.1] goes on to say that if both are used, stateful configuration should be preferred over stateless.

[RFC3646]: http://tools.ietf.org/search/rfc3646
[RFC4861]: http://tools.ietf.org/search/rfc4861
[Section 5.3.1]: https://tools.ietf.org/html/rfc6106#section-5.3.1