Missing machines

Tailscale version: 1.12.3
Your operating system & version: raspbian (debian) 10.10

I have 11 machines on my tailscale network (spanning macos, debian, oracle linux, android, and raspberry pi). Two of the machines, both raspberry pi’s, do not see eachother in their tailscale status output and cannot reach their respective tailscale IPs. They can reach eachother directly outside of tailscale as they are on the same subnet. All of the other machines can reach them over tailscale though! And they can reach other machines over tailscale. They’re just invisible to eachother.

I have tried stopping/starting, as well as deleting the tailscaled.state file, and removing the machines from the web ui and re-enabling them. But they always end up in the same state.

What things could I look at to try and troubleshoot why two specific machines would not be visible to eachother?

Their tailscale IPs are and

It looks like you’ve applied tags to those devices and there’s no ACL permitting that tag to talk to other devices with that same tag. If you untag the devices or add an ACL, it should solve your problem.

:man_facepalming:so simple. thanks!