So a strange issue. I'm quite unsure where to go from here. Unraid cannot ping, and cannot be pung by any device on the LAN subnet. My server lives at 10.0.0.50. I cannot ping it from any device on the same subnet, and it cannot seem to ping anything either. It can't even ping the gateway. And yet, it is fully accessible from my VPN subnet, which has to pass through the gateway to reach the server. Bizarre because anything in that subnet shouldn't even be hitting layer 3. And yet, even layer 2 communications fail. So what gives? Where can I troubleshoot this? Diagnostics included.

lilnas-x-diagnostics-20240531-2055.zip

I figured out my issue. My network routing table was causing my problems. ( I don't understand why it was a problem so suddenly, but that's a question to ask if it randomly happens again)

I have br0 and br1 for docker stuff. Two incoming connections, eth0 and eth1. eth0 is on my DMZ subnet and attached to br0, eth1 is on my LAN at 10gbps and is attached to br1. The metric for br0 was 1, while br1 had no metric. I changed br0 to 3 and br1 to 1 just in case I want to add a second 10gbps connection later. Now, traffic to and from the LAN network works fine!

The incorrect config caused issues because I have firewall rules to limit traffic to and from the DMZ. If traffic tries to escape the DMZ on any address besides the gateway, it is dropped. As such, pings to the 10.0.0.0/24 subnet would get dropped because unraid was routing outbound traffic through the DMZ due to that metric being too low on br0. Since it was DMZ traffic, it could not physically reach the LAN.

Edited June 2, 20242 yr by rjdipcord
clarity