DynDNS Problems

A common problem with SIM cards is that the router can't be accessed even a service like DynDNS is used. This problem has nothing todo with the router functionality because it is a general problem with IP networks.

Most likely the SIM card has a dynamic but only a private IP address. For using dyndns or similiar you need a public IP address

• Static means the IP address never changes as long as you stay with the same provider or same server. • Dynamic means the IP address can change from time-to-time. • Public means the IP address can be visited from any computer in the world. • Private means the IP address can only be used by those on the same network. Private addresses are: o 10.0.0.0-10.255.255.255 o 172.16.0.0-172.31.255.255 o 192.168.0.0-192.168.255.255

Please check if the IP address of the router in the mobile network is in the range of a private IP address:

Using services like whatsmyip.com will show you another address which is the address of the router of the operation. This is the same situation like a private DSL-Router at home which has a public (but dynmaic) e.g. 79.4.3.2) IP. If the local computers are on a 192.168.1.0/24