DNS Domain override not working with resolver

[Zotan]

I have 3 firewalls connected via a private network like this A <-> B <-> C I would like to use a fake domain for devices connected to C. I have setup both A and B to have domain overrides for that fake domain so that DNS queries are forwarded to C rather than being resolved in the usual way. For A this works. It runs the DNS forwarder dnsmasq and correctly forwards the requests to C. For B it does not. B runs the unbound resolver and if I sniff the DNS traffic between B and C no request is ever forwarded.

This appears to be the same behaviour as the in this thread:
DNS Domain Override Not Working

In the log for unbound on B I see:
May 22 14:10:30 unbound 7268 [7268:1] debug: sending to target: <fake.> X.X.X.X#53
May 22 14:10:30 unbound 7268 [7268:1] info: sending query: host.fake. A IN

But no packet is sent to C

So are domain overrides broken with unbound or has someone got them to work?

[Zotan]

I found the problem, hopefully this is useful to someone in the future.

Domain overrides do work with unbound. My mistake was that I had not enabled the interface to C in Services -> DNS Resolver-> General Settings -> Outgoing Network Interfaces Which explains why the requests were never being sent.