Problems with DNS resolution across VPN
I've got 2 VPNs setup on my pfSense. One is an OpenVPN on 10.10.100.0/24, the other is an IKEv2 Mobile Clients network on 10.10.69.0/24. My LAN is 10.10.42.0/24.
I have a DNS resolver running on the pfSense box (10.10.42.1/10.10.100.1) and a DNS server running bind9 on a machine on the lan (10.10.42.6).
From both VPNs I can successfully perform DNS resolution using the bind9 (non-pfsense) box. nslookup myserver.mydomain 10.10.42.6 works flawlessly.
From both VPNs I cannot perform DNS using the pfsense box (10.10.42.1).
I'm using OpenVPN on my linux boxes, and calling nslookup using the lan IP (10.10.42.1) results in "reply from unexpected source: 10.10.100.1", calling nslookup using the vpn IP (10.10.100.1) works. The latter is a fine solution and I can configure my DNS to push the pfsense's VPN IP, but the former makes me worried that I have misconfigured something.
I'm using IKEv2 on my windows clients so I can use the built-in VPN client. nslookup on 10.10.42.1 (or 10.10.100.1) results in a timeout. Like I mentioned above, 10.10.42.6 works great. I don't believe this is a firewall issue since I'm able to access other services on the pfsense box from the IKEv2 clients.