Port forwarding on 4G modem NETGEAR LB1120

[gammajuice]

I'm trying to configure the modem in a remote location, easier than having internet installed, and can't seem to get port forwarding to work.

I'm using a prepaid, hotspot line from T-Mobile. Inserted the sim into the modem, and it does work, devices can access the internet when connected.

Problem is, I don't know what is the public IP address, and port forwarding does not work. As an example, I have a linux server connected. I don't know if these 2 issues are related, but when I do a "curl icanhazip.com" in the server, it returns a different IP address from the one shown under Settings > Mobile > Status Details > IP Address (indicating icanhazip.com sees a different ip than what the modem is showing).

Neither of the ip addresses work when I try to ssh in, after setting the port forwarding settings.

(modem is in "router" mode, with port forwarding enabled, in this case for ssh, I have port 22 set with TCP)

I wonder if it is a t-mobile problem where I need to have them allow incoming traffic to a public IP address, if this is the case, please tell me what exactly I need to tell them because they don't seem to know very much...

Thanks.

[schumaku]

Check the Mobile > Status Details for the effective IP address assigned on the "air" interface of your AirCard. Many (not only mobile) ISP are run out of public IPv4 addresses a long time ago, do Carrier Grade NAT (CGN) and assign either the IANA allocated addresses from the 100.64.0.0/10 block (RFC6598) or Private IP (RFC 1918) addresses on the air interface.

[gammajuice]

Okay, but like I said I tried both IP address, so the IP address assigned on Mobile > Status Details does not work for remote ssh access after port forwarding was configured.

[schumaku]

To start with (and sorry when we're looping here): if the "what is my public IP addess" as seen from the router site and the IP address on the WAN interface is not the same, there is some CGN in place, and the "inner" IP on the WAN inerface won't be publically routed, so it can't b e reached from the wild Internet.

[gammajuice]

Is this fixable some way? Can T-mobile provide me with a public facing IP address?

[danhoo]

Did u ever get going? I am in the exact same position as u were. Thanks!

[schumaku]

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@gammajuice wrote:

Is this fixable some way? Can T-mobile provide me with a public facing IP address?

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@danhoo wrote:

Did u ever get going? I am in the exact same position as u were. Thanks!

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Talk to your mobile provider for public IP options.

xxx