DNS Conditional forwarding on 2.3.2-RELEASE-p1 (amd64) DNS resolver

honza · Jan 14, 2017, 1:12 PM

Hello erverybody,

I recently installed my first pfsense and I run in a problem I am not able to solve alone. I have a VPN tunnel into my employees network. The tunnel is working fine. For the problem I am decribing is important that I am able to open a nslookup connection to the companies DNS server and resolve names to local IPAdresses.

I added a conditional forwarder on the WEB GUI for this internal DNS server: Please see attached screenshot.

Full qualified domain names to the local domain are not resolved. If I perform packet capturing, I can see that my pfsense box is not trying to perfom a lookyp from that internal server 192.168.0.220. In DIAGNOSTICS==>DNS lookup the conditional forwarding server is not listed when I try to perform a lookup for that local domain.

I investigated a litte and found out, how I can have a look into unbound.conf. What seems strange is that I see no entry for the conditional lookup server. I only see entries for the local doamin listed as "private-domain" and "domain-insecure", but no entry for 192.168.0.220.

Can anyone help/advise ?

Thanks and regards

Honza

johnpoz · Jan 14, 2017, 1:30 PM

So if you want the resolver to query a dns server down a vpn tunnel. You need to make sure you set that interface to be able to be used for queries in unbound..

So I have a vpn connection to a vps, I set unbound to use be able to use that interface. I then setup forwarder for myprivatetestdomain.com to use IP on the other end of the tunnel.

I then do a query for something in that domain, and you can see from my sniff on the vpn interface that It asks that dns server - in my case it sends back refused since I don't have that ns setup for that domain. But you can clearly see it asked it. Now if your query is going to return rfc1918 address, then you most likely need to set that as private domain in unbound so that unbound will hand back any rfc1918 IP it gets to the client.

honza · Jan 14, 2017, 2:16 PM

Thanks for the repley.

I have set "Outgoing network interfaces" to "ALL".

But what is strange to me is that I do not see the IPSEC device under "Outgoing network interfaces".

Is that my problem ?

Thanks

honza · Jan 14, 2017, 6:12 PM

Hello,

I found a solution. I defined a Gateway on my LAN address and added a static route into the remote VPN network.
Now it works.

johnpoz · Jan 14, 2017, 10:12 PM

Ipsec is a problem..

Why would you define a gateway on pfsense lan?? That is sure not how he gets through the ipsec tunnel.

honza · Jan 30, 2017, 9:42 AM

Thanks for the repley.

The Gateway was really the wrong approach.

The real reason was, that I did not understand before, that "LAN network" does not contain "LAN address". So the FW blocked

the lockup from pfSenses DNS.