iptables not effecting

[brcisna]

Hello All,

Brand new to cellular internet access. Very familiar with iptables.
Using an sierra wireless modem inside a Debian Bullseye box, and really having troubles to allow a few ports open into the box such as ftp, http.
I have what i think is correct entries in both iptables and ip6tables. to allow these ports to accept along with forwarding.
When i do a port scan from whatsmyip org there absolutely no ports open.
Sure seems simple enough but have never delt with a modem as an interface before either. Is it possible the provider is using some sort of nating that is nixing the iptables settings.

Thanks

[mtl26637]

All cellular modems set behind CGNAT (carrier grade NAT). No access from the outside unless on specific plans through the carrier. Reverse ssh tunnel is typical solution for most I think. Might explain your issues?

[brcisna]

mtl26637

Thank you for explaining this . New to cellular setup. Just wanting to access server from time to time out on the road. To have ftp, and ssh once in a while. Couldn't even access via Anydesk,,,dont think? Haven't tried Anydesk yet.
This surely explains why iptables are doing nada. As much as have messed with networking stuff just never used cellular.

Thanks again

[LoveMeSomeCALTE]

SSH tunnel over a public VPS - or use something like ngrok.