Hi everyone,
I’m running AdGuard Home on my TrueNAS server to handle DNS, but recently the DNS server completely stopped working. DNS queries are timing out, and AdGuard reports that upstream DNS servers like Cloudflare or DoH URLs are unreachable.
I started troubleshooting and found that while TrueNAS has the correct default route set through my gateway, it can’t actually reach the gateway. When I try to ping it, I get a “Destination Host Unreachable” message. The network interface on TrueNAS (a bridge I set up for NetBird) is up and shows no errors. Meanwhile, other devices on my LAN can reach the gateway and access the internet without any issues.
Here’s where things get strange: despite not being able to reach the gateway, the server is still fully accessible from the LAN. I can stream videos from Jellyfin and access SMB shares without a problem. I can even use NetBird to access those services remotely, outside of my home network. So traffic is clearly getting in, but TrueNAS itself can’t seem to send anything out — not even basic pings to the router.
The bridge setup seemed fine when I first configured it. I moved the IP alias from the Ethernet interface to the bridge so NetBird would work properly, and everything ran smoothly for a while. But now, even if I try to revert that change and put the alias back on the Ethernet interface, it doesn’t fix the problem.
This feels like some sort of local routing issue — maybe a problem with how the bridge is configured, or something strange at the switch or firewall level. I’m wondering if anyone else has run into this kind of one-way connectivity issue before, or has ideas on how to dig deeper and restore full network access from the server.
Thanks in advance!