Where does Tailscale Apply IPTABLES Rules?

Hello all,

I have Tailscale running under Debian in use as a subnet router.

I need to add an IPTABLES rule and make it persistent. My problem is that, upon reboot, IPTables-Persistent does not appear to be applying the rule I’ve added. When I manually restart that service, it applies the tables. Based on what I’m reading elsewhere, this can happen when something else is overwriting the rules later in the startup process.

Given that there are Tailscale rules present after the reboot, I am suspecting Tailscale is overwriting the IPTables values.

Where is this applied? (is a configuration file being called in some startup config file?) I would like to go there and add this rule. Otherwise, I may try to figure out how to set up a script to add the individual line later in the startup sequence.

Thank you