Only one device fail to connect to internet

[vickvohoang]

HI, I’m new to this and starting setting up OPNsense on my pc router using Proxmox 1 month ago. Recently something stragne happens when my main PC (Windows 11) start disconnect to internet but can still access to LAN except for the OPNsense router IP. Every other device working perfectly fine. At first I thought it was cable issue and started to troubleshoot everything and the all the connection are fine. Even weirder the PC would occasionally able to connect to internet but then would disconnect again after a while or after reboot. I think it might be driver issue so I reinstall and roll back drivers, not luck. I tried to install Linux on a different drive just to test and it works fine on the same machine. So I decided to reinstall Windows and it disconnect again. I have a backup OPNsense in my proxmox and it works fine whenever I use it instead. The only diffrent between the backup OPNsense and the main one is the backup is running CARP and have a diffrent default IP address (10.10.10.1 vs 10.10.10.251). I was using CARP when I tried to messing around with HA for OPNsense but decided to use 1 firewall on the current instance of the OPNsense. So now i think it CARP or HA setting related. I’m new to this and still learning while messing around so some terminology maybe incorrect, so feel free to question me. Any ideas?

[bartjsmit]

What tests do you do? Ping 8.8.8.8 is better than using a browser for instance since the firewall is a layer 3 device while the browser is on layer 7.

Do a ping and a traceroute from a working and non-working device to confirm it really is the firewall.

Bart...

[vickvohoang]

when I ping 8.8.8.8 it times out, when I ping 10.10.10.1 (router ip) it came back but still can't access it via browser

[bartjsmit]

what about traceroute? Is the firewall in the path to 8.8.8.8?

[vickvohoang]

I don’t think so, but can you show me how I can check for it?

[bartjsmit]

If your PC runs Windows, open a command prompt and run:

tracert 8.8.8.8

Bart...

[vickvohoang]

it’s request timed out

[bartjsmit]

Is the firewall IP in the list of hops, or are there no hops at all?

[vickvohoang]

no hop at all

[bartjsmit]

That means you don't have a default gateway set up.

Open your network config and add 10.10.10.1 as the default gateway.

Bart...

[vickvohoang]

on the PC? in the network setting I can see it detects the default gateway correctly

[bartjsmit]

Is it Windows? Reset the stack from a command prompt:

netsh int ip reset
netsh winsock reset

reboot and try again

[vickvohoang]

it works but after about 30 minutes or after the PC went to sleep, I disconnect again. If I go to proxmox and restart OPNsense it will works until PC went to sleep.

[vickvohoang]

UPDATE: another clue: whenever this happens, I can go to the Proxmox console for the Opnsense and choose to restart all services and it worked

[vickvohoang]

When the PC is disconnected I can see a bunch of request in the firewall log of OPNSense from the PC to outside IPs but no response. This stop as soon as I restert the OPNsense and the PC is reconnected. what could this be? Please help.