PowerDNS IPv6 PTR Global Wildcard

[SwimGeek]

Hi

I'm looking for some advice on setting up PowerDNS so it answers IPv6 PTR queries with a global wildcard response.

IPv4 is easy enough, just add one wildcard record per zone, but IPv6 is going to be a big pain to maintain - too many zones - too many client /48s.

Know of a way to tell the Powerdns that for anything in a /32 network which does not have an existing PTR record, answer with ‘wildcard answer’ ?

I noticed RFC 8501 talks about this problem, but after lots of web searches I can't find a solution.

Using pdns-server 4.9.3 with mysql backend.

[SwimGeek]

maybe it can support having a record like:

*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.*.8.9.8.e.f.f.c.2.ip6.arpa

[Habbie]

we are limited by the DNS specifications in how we handle wildcards, so this won't fly.

that said, I don't understand why your problem is hard for v6 if it's easy in v4.

[SwimGeek]

Hi, I set up the wildcard for v6 in the same way as v4 - but it does not work the same from my testing.

I found this: https://github.com/endreszabo/PowerDNS-Dynamic-Reverse-Backend

Will try that next.

[omoerbeek]

When reporting "something does not work", it helps to show exactly what you did, what you expected to see, what you actually saw and explain how that made you decide it did not work.

[SwimGeek]

Hi, for IPv4 - I added a wildcard on the /24 level - and the smaller networks below that all worked - probably because IPv4 has simple 'classful' lookups.

For IPv6, I added the wildcard on the /32 level, but the smaller networks under that did not work. Did not return the wildcard when looking up the PTR record.

[Habbie]

We cannot debug a vague description of a situation :) please -show- what you did and what happened. Keep https://blog.powerdns.com/2016/01/18/open-source-support-out-in-the-open in mind!

[SwimGeek]

No stress. I don't think modifying the DNS server is the solution. I think I need something to intercept the query, see if a record exists, if not return a wildcard answer for the full /32 range. - I'll look into the Dynamic-Reverse-Backend option I posted above.

[omoerbeek]

You were looking for advice, but not sharing details, so wasting everybody's time.

Check https://docs.powerdns.com/authoritative/lua-records/functions.html#reverse-dns-functions, they might do what you want.