CGNAT Help for Newbie

OK, sorry if its been covered. And sorry for the long winded preamble. I am new to Tailscale. Better than average with networking amongst regular humans but nowhere near the level of understanding when reading help docs on tailscale. I am not good with Linus. New to TMobile 5g home. Understand about CGNAT now and like everyone else…annoyed by its limitation. Love the speed and don’t actually have any other options where I am at. Was using Verizon Home 5g but speeds are not great. The only limitation I have is I use port forwarding to access my home automation (with the IOS app SnapLink) and no-ip dns. I understand why that won’t work with TMOB home 5g gateway. Thought TailScale could get it to work but I am failing. I have a windows machine, always on and installed TailScale. Installed it on my iPhone as well. I thought that would make my iPhone effectively “think” it was on the local network and then I could just log into the app as I would when the iPhone is on wifi at home but I can’t make it work. I am using a very old home automation system (HAI OmniPro II) with a fixed IP address that is in the same subnet as the windows machine at home. There is only one app that is currently working to access that home automation that I am aware of (SnapLink) . I have 2 setups for SnapLink… one for when I am home on the wifi (and the address is just the internal IP for the motherboard of the home automation) and another account in SnapLink for when I am away and it is directed to use the DDNS from no ip (which works with the verizon home 5g).

Can anyone suggest how to utilize TailScale to accomplish this with T-Mobile Home 5g Gateway? Am I missing a step? Should I use something different like Cloudflare?

Thanks and sorry for the long post!

Try this: Firstly, make sure tailscale is running.
Right the icon and do this:

  • Hover over “preferences” and make sure everything is ticked - but dont reset to defaults.
  • Next, hover over “ext node” and tick “run exit node” and “allow local network access”

Log in to your Tailscale admin portal and follow this guide (step 2)

Now, on your phone, connect to the tailscale vpn (try both the exit node and not the exit node).