[Archer C2600] Randomly losing all connection on WAN interface

Installing and Using OpenWrt Network and Wireless Configuration
1

I am not sure where I should start with this.

Current setup:

  • TP-Link Archer C2600
  • extroot

It all started with installing 24.10(.1). I wanted to get up to date before installing Tailscale on the router. I then moved the installation to a usb stick, because Tailscale would not fit on the flash memory.
After that I installed Tailscale and set it up as mentioned in the docs.

Then it started. I experienced random connection losses.

I first thought it was a routing issues, because I could not browse websites or ping anything from LAN.
then I found out, that I could not ping from router via SSH either.
I tried restarting the WAN interface over the web interface, it came back up but never got a new IP, which lets me believe that the issue lies somewhere else.

The only way I could resolve this issue is by either restarting the router OR service network restart. Afterwards everything works again.

The only scenario I can reliably reproduce the issue is when I try to access something over the tailnet from the outside. I am not sure if and how that is related. If it would be a routing problem, I could see why this would happen if the tailnet is used, but since the IP is not coming back I am not really sure what is happening here or where to start debugging the situation.

If you have any tips or commands or logs you want to see, please tell me :slight_smile:

Appreciate your time

Edit: It has nothing to do with Tailscale. It happens either way. I realized that after I installed 24.10.1 over 24.10.0 as a measure to try to bugfix this issue.

2

From a fresh install, I still have this issue.
Since everything worked fine with 23.x, my bet is on DSA. I am not capable of debugging this by myself, so I need help, please.

Maybe it has something to do with empty bridge interfaces that are used for Guest WIFIs setup with this tutorial: https://openwrt.org/docs/guide-user/network/wifi/guestwifi/configuration_webinterface

Maybe it is something else.

The bug is flakey and the logs are basically empty.

Only way to fix the issue is with a service network restart or a complete reboot.

3

I was searching for bugs before installing 24.10.1 because I had this problem with 24.10.0, but it seems it still persists.

The only problem is WAN? By the time I was testing I thought it was the whole network and not jut the WAN.

I tested with a factory reset and it still happens.

By any chance did you try to swap the firmware as stated in the wiki? https://openwrt.org/toh/tp-link/archer_c2600_v1#alternative_wifi_module_and_firmware

4

My setup is pretty simple.

LAN clients could still talk to each other perfectly fine.
LAN could not reach WAN.
ssh'ed into router and tried to ping the modem connected to WAN or the internet was impossible.
restarting the WAN interface from LuCi removed the ip but did not assign a new one (guess DHCP could not be done). Assigning a static IP to WAN did nothing either. Same goes for WAN6.

I have not tested the guest (wifi) interface, since it has client isolation anyway, hence I just leave this out of the equation. Especially since the problem first occurred when there was no guest interface anyway.

Regarding the firmware: as far as I see that only concerns WIFI. Since I have tested everything with cables, I fail to see how they might be related.
I could connect to the wifi at any point and even visit LuCi from the devices, but no internet connection or any other WAN related connection was possible.

Do you really think that a wifi driver could cause WAN to completely fail?

5

Oh. hum. I was connecting via wifi and lost connection all together. I have to retest, but according to your reports I don't have much hope.

By any chance did you open a bug report?