Network Connectivity Issue with Raspberry Pi K3s when Tailscale's advertise-routes is Enabled

[hxpmc]

Description:
In my local network environment, I have a Linux machine already deployed with Tailscale and advertise-routes enabled. After installing K3s on my Raspberry Pi, it causes a network issue where I can no longer connect to the Raspberry Pi using its local IP address.

Upon reviewing the code, I found that it executes tailscale set --accept-routes. I am unsure about the specific role of this mandatory accept-routes setting. Is it possible to make this configuration optional?

[brandond]

It needs to accept routes to send traffic to pods on other nodes; without this pods won't be able to communicate.

What routes do you have that are preventing lan traffic from remaining local? Have you tried correcting your tailscale routing tables?

[hxpmc]

I already have a machine with --advertise-routes=192.168.6.0/24, and the Raspberry Pi's local IP address is 192.168.6.225. I consulted Gemini, and it informed me that this configuration could create a routing loop.

[brandond]

Why did you do that?

[hxpmc]

Simply because that machine is acting as my software router.

[brandond]

@manuelbuil might have some suggestions on ACLs or other things you might be able to do on the tailscale side, but I suspect that having one node advertising a route to to your entire LAN in the same mesh as you have Kubernetes nodes advertising routes to pod CIDRs is not going to work.

[manuelbuil]

@rbrtbnfgl is now looking into Tailscale more deeply :). I hope he can reply