Replicating DD-WRT DNS lookup behavior

[Frotz]

I'm trying to migrate a DD-WRT setup to OPNsense 25.7 and there's one final hitch -- DNS lookups.  Under the DD-WRT setup, a client on the internal network would get the correct result when looking up each of these:

• host-internal.mydomain.com
• host-internal
• host-external.mydomain.com
• host-external

The host-internal hosts are assigned IPs through DHCP.  Some of them are handed static addresses.  The host-external hosts are VMs at hosting services.  When I try to get OPNsense to handle this, some work and some don't.  Exactly which does and doesn't changes depending on what parameters I tweak or services I use.  Frustrated with this, I tried using ChatGPT and had the same problem.  Note: in "System: Settings: General", the domain is set to "mydomain.com".  Some of the rabbit holes I went down with ChatGPT suggested that KeaDHCP would do what I want, but that functionality is not exposed in the OPNsense user interface.  Meanwhile I keep getting suggestions of how to trick OPNsense into doing what I want, but these keep going in circles.  How do I get this working?

[nero355]

My best guess is that DD-WRT uses DNSmasqd instead of ISC or KEA and you might want to dig through the config files on your DD-WRT Router to check if that is indeed the case.

DNSmasqd does both DHCP and DNS while ISC and KEA depend on Unbound for DNS stuff...