Hello,

I would like to use 2 WANs on my hap ac3. Looks like simple job.
But
1st step
instead of load balancing/classic failover I want to have to keep Tailscale traffic always use the LTE (usb modem) connection.
For rest of connections I would use network from "normal" WAN - connected via the RJ45 and IP delivered through DHCP server. (DHCP client on mikrotik side).

And would be great if that is possible - in 2nd step - use LTE connection as a failover if "normal" WAN will be down.

Is it possible to obtain that (1st step)?
Why I want to route specific Tailscale? Due to unpredictable load on "normal" WAN. I would like to have alway working connection to Mikrotik through the Tailscale.

To be honest - at this moment I am using Tailscale on end devices only, but I really want (and I will try this weekend;) to work with container which will alllow Tailscale traffic at network level (Mikrotik as Tailscale router).

Have a good weekend,

To do that, you need to identify "Tailscale traffic" before a connection is even established. I.e. it has to have some identifyable protocol, portnumber, destination host etc.
Unfortunately I cannot find that information on the website, you will have to research that yourself.
Once you know the characteristics of the traffic, you can use route marking to send it over the desired connection.

One possible way to identify the TS traffic might be using the WG and STUN ports: www.tailscale.com/kb/1082/firewall-ports/