Closed Ports - Port Forwarding

Hi, I use a ZBT-WE826 (16M) running Open WRT 18.06.7. It has a Sierra Wireless EM 7455 modem running on the ATT network ( I live in a rural area so this is how I get internet).
I'm not very IT savvy but I'm trying to learn.
I'm trying to set up a Minecraft server. But first I'm trying to get any port working.
My first issue is it appears ATT blocks all of my ports.
My lsof scan on the router says port 80 is listening.
However, both and tell me they cannot see service on port 80 using my public IP address.
Just to confirm what I suspect, does that mean to you my ISP is blocking the port?

Most likely you do not have a public (routable) IPv4 address on your WAN. Nowadays almost all mobile broadband customers are behind CGNAT. In such a situation, it makes no sense to talk about ports.


More likely is that AT&T is assigning you a NAT or CGNAT IP address. If so, you actually do not have a public IP address of your own, so you will not be able to setup any port forwarding to enable inbound connections.

What is the IP address on the wan of your openwrt router (just the bold part is fine: aaa.bbb.ccc.ddd)

And if your modem is not a configured as a true bridge, can you see what IP address it reports?


I think you two nailed it with the CGNAT.

My WAN IP on my router is 107.77

Right now it's not configured as a bridge.

Please show a proof from your router, not from any external web site.

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This should be my WAN IP - the other one I posed was My public IP

then WAN IP on your router is not 107.77 as it was stated above, so technically you do not have a public IP, the public IP address you may see on the external web site is not yours, it is shared between multiple subscribers.


10.16.x.x is from private NAT address space. Quite similarly as 192.168.x.x
(Also the DNS address 172.x.x.x likely is a NATted private address from 172.(16-31).x.x space. Typical for ISP NATs.

Apparently you do not have a public IP, so you can't forward ports.


But that 10.16.x.x is from your router, right?
So it sees the network provided by the modem (which is not bridged, you said)...

It is possible that the 10.16.x.x is provided by the modem,
while 172.x.x.x is then provider by ISP for the modem.

What does modem's config show as its own WAN address?
(And as it is not in the bridge modem, you should do the port forwarding there, if possible.)


Yes, it is provided by the modem, but this modem is transparent in MBIM (and QMI) mode, so this is exactly the same address that is provided to the modem by the carrier.

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