This issue is not constant. From my last post, I didn’t see this issue and I didn’t change anything. Tailscale is enabled all the time.
Maybe this error message appears sometimes but I probably missed it because it doesn’t interrupt my connection. I still can load sites and I don’t spend a lot of time in the admin panel.
It’s back. Looks like it is certainly related to Tailscale.
Current issue status
on Macbook I can use Internet access with no issues. It just works. Tailscale client is not enabled. But I see the same errors in the Admin panel.
On Windows PC I don’t have access to the Internet. It is what I see in the Admin panel
Interestingly, I can connect to Tailscale from a Windows PC. When Tailscale is connected I have Internet access. I can’t explain why. And I can’t access the router admin panel when Tailscale is connected.
192.168.8.1 nor Tailsclae’s IP work.
Sometimes, in the admin panel, I can see the error message “No WAN cable detected” or something like that.
Only manually removing the cable from the router removes this error state.
Could you please ssh login this router, then try with these commands?
sed -i 's/route_param="$target dev $dev"/route_param="$target table main"/g' /usr/bin/gl_tailscale
sed -i 's/\/sbin\/ip route add table local $route_param/\/sbin\/ip rule add from $route_param/g' /usr/bin/gl_tailscale
sed -i 's/\/sbin\/ip route del table local $line/\/sbin\/ip rule del from $line/g' /usr/bin/gl_tailscale
Should I try to run these commands when this issue is active or it doesn’t matter?
Now this issue is gone after I removed the WAN cable.
Should I wait until it comes back?
Fixed the code format. Pls try again.
Now commands work.
What should I do next? Just wait for the error again? Should this error be gone?
This is what we are expecting you to check.
Pls let us know if this happens again.
All, I am getting a very similar error. I am also a Tailscale user. I was able to use my GL Beryl MT3000 flawlessly for months as a subnet router pointed to an exit node for months with no issue at all. I have done all of the standard Tailscale setup, etc. As I said it was working for months.
I recently moved and it stopped working. I had made no other changes to the router at all before it stopped working. Then I ran into an issue where using the Tailscale exit node bricked my internet. As soon as I turned this off it worked again. Though I never had to so this initially, I setup a firewall zone and interface like is mentioned here: Help to configure tailscale as a proxy service - Installing and Using OpenWrt - OpenWrt Forum
This fixed the issue of the Tailscale exit node completely killing my internet, but it makes no change to the external IP when I check whatismyip. I disabled mwan3, but that did nothing.
Now I am currently getting the “The interface is connected, but the Internet can’t be accessed.” error similar to what a lot of others here are getting, and similar to them my internet works fine without issue despite this error. It displays whether Tailscale is on or off. I ran the commands that were supplied above in this thread and this did not fix the issue. I’ve tried several different firmware versions,but am currently on 4.2.3 because that seemed like it was the most stable.
The only thing that I changed that caused this not to work was moving and connecting to a new modem. As you mentioned above, is that possibly what the issue is? You mentioned changing the WAN IP, but I can’t do this as it is not my Modem. Do I need to change the subnet route of the GLiNet and/or change the LAN IP from the default 192.168.8.1?
Any help would be greatly appreciated.
Update:
I manually installed version 4.4.5 and this fixed the no internet connection error message, but doesn’t fix any of my Tailscale issues.
Does anyone have the firmware 4.4 I am getting the same error wifi and hardwired. It will work for a few hours and drops the connection.
If that fixed the issue then ill do your solution and never update the firmware again.
Does anyone have this issue with update version 4.5 ?
Maybe just have a try.
I tried it and I am still having outages. It will go out for 5 minutes and then come back. It acts as if there is no ethernet plugged in for a few moments.
Does any one have the 4.4 file I can revert to please 
I am currently experiencing this issue after updating my Opal SFT1200 few days ago.
I have two different internet ISP’s. When I connect from ISP Router A to my Opal through WAN port, I get this error and unable to access the internet.
When I connect from ISP router B, I do not get the error and my Opal router works fine.
Any assistance will be highly appreciated.
Also before the issue started yesterday, i was always on Router A without any issues.
