I’m running AdGuard Home on my TrueNAS box for DNS, but recently all DNS lookups started failing. AdGuard reports upstream DNS servers (like 1.1.1.1 and DoH URLs) as unreachable.
TrueNAS has a default route via my gateway (192.168.2.1), but it can’t ping it — I get “Destination Host Unreachable.” The network interface (br0) is up with no errors.
What’s confusing is that local access still works fine — I can stream from Jellyfin and access SMB shares from other devices on my LAN. Even externally, through Netbird VPN, I was able to stream from Jellyfin. So TrueNAS is clearly reachable from inside and outside, but it seems like it can’t reach out — no internet, no access to the gateway.
I had previously moved the IP alias from the NIC to a bridge (br0) to use with Netbird. That setup worked for a while. I’ve now deleted the bridge and put the alias back on the NIC, but the issue persists.
DHCP is enabled on my router, and other LAN devices are working fine. I switched the global interface setting from br0 to automatic in TrueNAS as well.
AdGuard started acting weird when I pointed my router to it for DNS. I’ve since removed those settings and shut down AdGuard, but the problem remains. TrueNAS can’t fetch updates or connect to anything outside the LAN.
Feels like a routing issue or IP conflict, but I’m not sure what else to try. Any ideas?
Under the Network Settings, “Global Configuration” is the gateway 192.168.2.1 and if so is it attached to that same subnet? What happens if you SSH into TrueNAS and ping 1.1.1.1?
On my network settings, yes, that is the default gateway. When I use the shell on the TrueNAS web interface, not only can I not ping 1.1.1.1, but I cannot ping my default gateway either.
Will SSH’ing into it change the outcome if I try to ping?
Hey, it sounds like a tricky networking issue! Since TrueNAS can’t ping the gateway but local LAN traffic works fine, it definitely points to a routing or interface configuration problem.
Given you moved the IP alias between the NIC and a bridge, I’d double-check these things:
Verify the bridge (br0) is fully removed and no leftover config is conflicting with the NIC IP settings.
Confirm the default gateway is set correctly on TrueNAS (you might want to run a route print or equivalent to see if the default route points properly).
Check for any firewall rules on TrueNAS or your router that might block outbound traffic.
Sometimes IP conflicts or stale ARP entries cause weird “host unreachable” errors — try rebooting your router and TrueNAS to refresh these.
Since DHCP is on the router and other devices are fine, maybe TrueNAS is still holding on to an old IP config—try renewing the DHCP lease or set a static IP that’s outside your DHCP pool.
Also, confirm there’s no VLAN tagging or bridging left in the TrueNAS network config that might confuse packets going out.
If nothing else, setting up a temporary simple network config (just NIC with static IP and gateway) might help isolate the issue.
