Question

Hi,

I am looking to configure a RUT955 modem with an LTE SIM with fixed private IP address for remote access over a VPN. The other end of the VPN is another PC that is able to ping the LTE SIM IP when it is connected to a phone. However ping fails when the SIM in inserted into the RUT955.

So I believe the RUT955 needs to be configured with  IP/port forwarding on the WAN-LAN interface. I have set up the modem in Bridge mode and enabled full port forwarding to the PC connected to it. All firewalls rules are set to accept since its a trusted network.

The network diagram is here: https://www.draw.io/#G1026pnHSEAVdYdnTxfii1NpQulMNTMqa8

Any pointers on how to address the problem are welcome.

Thanks,
S

Answer 1

you will need to adjust the routes to send all of the traffic from the RTU through the VPN.   When the SIM is inserted the routes are adjusted as the SIM provides authorization for internet access via LTE.

If you are trying to provide a static ip address to the RTU via a VPN this may not work due to a ton of networking challenges related to interface mapping.  You may want to check with a network professional regarding virtual interface bridging over OpenVPN.   This is a rather complex topic that would require some work on the "PC" that is acting as the head end.