If you have IPv4 addresses, I guarantee you’re behind at least one NAT gateway. What you need is a Tailscale subnet router, or something equivalent from another service.

In the most basic configuration, the Tailscale client facilitates communication between one host it is running on and another host it is running on that are both connected to the same tailnet. For this purpose, it uses addresses from the 100.64.0.0/10 “shared address space” subnet. These addresses will only be reachable from within your tailnet.

If you want an entire subnet (e.g. your LAN) to be accessible within your tailnet, you need to set up a subnet router. This involves configuring the Tailscale client on a device within the target subnet to advertise routes (tailscale set --advertise-routes=192.168.1.0/24), allowing the host to advertise routes in the admin page (Machines -> … -> Edit routes), and configuring the Tailscale client on external hosts to accept advertised routes (tailscale set --accept-routes).

If you want your servers to be accessible from anywhere on the internet, you’ll need Tailscale Funnel. I don’t use it personally, but it seems to work.