DNS issues between interfaces

Started by Usr0815, April 17, 2024, 10:58:53 PM

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I am new to OPNsense, I just set it up today.
Maybe someone can help me, here is the issue:
I have my standard LAN interface (192.168.50.1), under which I have a pihole running (192.168.50.10).
I wanted to use the third port (opt1) on the server OPNsense is running on as a dedicated port for all things connected to Jellyfin. I have this connected to a port on my second server, which all the containers are using, so I set it up as a seperate interface (192.168.30.1). Somehow when I enter my piholes ip address as the dns server, the containers are not able to establish an internet connection, but when I set it to the cloudflare dns, everything works. How do I fix this? All my devices on the LAN interface also use the pihole and they are running fine.
For setting up the network, I just set up two firewall rules, identical to the ones automatically created for LAN. (except for the source of course).

Maybe someone with a bit more experience can tell me what is going on.
Thanks!

Hi,

you could start debugging this situation with Firewall's Live View. You'd probably see many UDP towards port 53 packets being rejected (my guess). If these are blocked with "default deny / state violation" you may try the following:

Generate a TCP/UDP allow rule on OPT1 towards your PiHole's IP on port 53. I would also recommend writing this IP as alias for less maintenance in the future. Any other more general rule matching this requirement will also work.