Occasionally there are some inquires about the IPv4 address (or internet IP address) on the 4G routers.
Here I will list some common cases and hope they will provide some help.
Case 1: the IP address via https://www.whatismyip.com/ is not the same as IPV4 IP on the 4G routers.
Case 2: DDNS/Port Forwarding /Remote Management is not working even though the configurations have no mistakes.
Case 3:Xbox/Playstation shows NAT type as strict or type 3 when playing online games.
The reason for the above issues is, when the router connects using your standard 4G Data SIM card, the mobile network provider will allocate your router with a PRIVATE IP address on their network. In other words, outside of the 4G routers, there would be another powerful firewall/gateway on the ISP side to monitor and protect your network.
Private IPv4 addresses are IP addresses that fall within any of the following ranges shared by @woozle and Thank you:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
100.64.0.0 - 100.127.255.255
If you have the same issue, please check the IPv4 address on your router and compare it with the IP on https://www.whatismyip.com/. If you found they are different and the IPV4 address is in the private IP range, please contact the SIM carrier to ask for a public IP.
Please feel free to comment below if you found something new that might be related to this issue.
Thank you very much.