I’m connected via a 4G modem. Got this setup about 3 years ago. In the beginning it was enough to look for the public IP (what’s my IP). The modem showed some sort of private ip in the ui. I’m running stuff at home (Homeassistant, Gitea,) and bought a domain and pointed it to my home IP via Cloudflare. After some time I’ve noticed my modem shows the public IP also internally. For about 2 years now it ran flawlessly, the IP changed from time to time, but not really more than once in several weeks. For about a week all stopped working and the modem shows IP 100.xxxx and outside 85.something I guess I’m behind NAT now. Normal port forwarding on the modem is useless now. Is it possible to open the ports via UPNP? I’ve tried via miniupnp from my Ubuntu server, but it just throws an error.

upnpc -a ifconfig enp1s0| grep "inet addr" | cut -d : -f 2 | cut -d " " -f 1 22 22 TCP

Can I use this to somehow open the ports via UPNP on my modem and bypass the blocking? I can’t even OpenVPN to my modem anymore.

EDIT: i also run AdguardHome, that I use as Private DNS on my Android phone

UPDATE: everything except Adguard Home used as Private DND on my Android works! I’ve used this: https://github.com/mochman/Bypass_CGNAT/wiki/Oracle-Cloud-(Automatic-Installer-Script) - free Oracle VPS + automated well described script. Even HTTPS works fine!

  • @[email protected]English
    2•1 year ago

    I’m actually not sure you can easily get tailscale up and running om such as a setup as it uses the same cgnat ip range.

    • @[email protected]English
      9•1 year ago

      This page says (at the very bottom):

      Tailscale can route its packets peer-to-peer over IPv4 or IPv6, with and without NAT, multi-layer NAT, or CGNAT in the path.

      • @[email protected]English
        2•1 year ago

        Yeah, you’re absolutely correct. I misread that thinking OP would have the CG NAT endpoint and taikscsle on the same physical device, which, I still think, would be a problem: you’d have two interfaces for 100.64.0.0/10. But if CG NAT terminates on the modem and you run taikscale on devices connected to it them there’s surely no issue at all.

        • @c10lEnglish
          2•1 year ago

          I run it on my router which has the CG-NAT IP address.

          Whilst you’re right that it could clash, it’s very unlikely (a 1 in 4194302 chance), I imagine Tailscale would detect the clash and change IPs though I could be wrong as it never happened to me (and probably never will - though in all fairness it will eventually happen to someone).

          • @[email protected]English
            2•1 year ago

            I went looking into how that works, and, apparently, tailscale adds individual node routes (in table 52). So yeah, you have very low chances of getting into trouble even if you have an interface with 100.64/10.

    • @c10lEnglish
      6•1 year ago

      Been using Tailscale behind CG-NAT for years. It works wonderfully and very rarely needs to route through the DERP infrastructure - it’s almost always a P2P connection.

    • Greg ClarkeEnglish
      2•1 year ago

      I haven’t had any issues running Tailscale and cloudflared on the same machines