I have a very strange problem with my TP-Link Archer C7 v2....
Around two months ago I started configuring some more interfaces for splitting my network. Additionally I wanted to make those VLANs accessible for my second AP. So I came up with this switch configuration:
This worked out until Tuesday night when suddenly I lost internet access on all devices (I did not change any config since at least one month).
Solving the problem:
Reboot: Everything looks fine but does not work
Check swconfig: Looks fine
Reset switch with swconfig and reboot: Looks fine but did not help
Remove all VLANs except WAN (1): Works
Add the other VLANs again: works
This was strange enough....
6h later:
Same problem again... I knew how to solve it....
Next day:
So I checked for a firmware update and upgraded to OpenWrt 19.07.6 r11278-8055e38794 / LuCI openwrt-19.07 branch git-21.022.31068-7129723.
This night:
Same problem once again. At least the solution was the same, too.
Conclusion:
Two different firmware versions
Switch deconfigures without any config change
reboot does not help
swconfig always shows a proper config
Simplifying and then redoing the config solves the problem
Does anybody know this problem? How can I solve it?
I would also check (keep checking, in case you notice problems next time) and taking a closer look (potential file corruption?) at /etc/config/network.