I encountered something I don’t quite understand, and I was hoping someone could enlighten me.
I set up Tailscale on my router with subnets, so I could remotely access my home network. This worked great. Then, at home, I was happily browsing the internet on my main PC, and decided to dial into another machine on my network. It couldn’t access it at all. Disconnecting Tailscale on my main PC restored lconnectivity.
I don’t understand what is happening here- the only thing I can think of is that my internet traffic was being routed through Tailscale, but I don’t have an exit node.
TL,DR: home PC sees Internet but not LAN when connected to Tailscale, why and how fix?
How did you set up subnet advertisements on the router, and which subnets? Did you touch the ACL in the tailnet’s admin console?
On the home PC, did you accept advertised routes with the Tailscale client?
What happens when you ping a host on the LAN using
tailscale ping ADDR? What happens when you try totracertortracepathto it?I set up subnet advertisements by doing
tailscale set --advertise-routes=192.168.1.0/24. I did not touch ACL.The home PC is Windows, the context menu for the tray app give the option to ‘use tailscale subnets’ which is enabled- I assume this is the equivalent of accepting advertised routes.
From the home PC, tailscale ping 192.168.1.2 returns a pong, from the tailscale IP. tracert fails.
That’s unfortunate, I have no idea how Tailscale does routing on Windows. Try running the client without accepting any subnet advertisements.
I’ve also found this: https://tailscale.com/kb/1023/troubleshooting#lan-traffic-prioritization-with-overlapping-subnet-routes The solution might be to advertise a larger subnet (e.g. 192.168.1.0/23) to make the route advertisements on the tailnet less specific than on the LAN. Advertising a larger subnet won’t cause any additional issues because it’s in a private IP range.