subscribe to our Youtube


14455 questions

17168 answers


0 members

We are migrating to our new platform at Moving forward, you can continue discussions on this new platform. This current platform will be temporarily maintained for reference purposes.
0 votes
613 views 1 comments
by anonymous

I tried to establish communication between two PCs over 2 routers (1PC --> 1R <--> 2R <-- 2PC). Routers have SIM cards and they are on the same network ( I have OPCUA client on PC2 and I need to read data from 1PC where is OPCUA server. My idea is to create port forwarding from 1PC through the 1R and 2R but I'm not sure how to configured port forwarding.

PC1 - IP Address:,  Default Gateway:

Router1 - WAN IP Address:, LAN IP Address:

Router2 - WAN IP Address:, LAN IP Address:

PC2 - IP Address:,  Default Gateway:

1. Can someone explain to me what is Source IP, Destination IP and Internal IP in port configuration?

2. What is the easiest way to solve this problem? I tried using PPTP, L2TP, Static Routing and Port Forwarding but unsuccessfully.

1 Answer

0 votes
by anonymous


Your WAN IP addresses belong to a private IPs pool. Apparently your ISP additionally performs CG - NAT before allowing you to access public internet. Due to this, port forwarding and majority of VPN protocols will not work in your case. 

Please check this ZeroTier VPN configuration example. This might help you solve your problem as this VPN solution does not require you to have a public IP, simply access to the internet:

You can also check Teltonika's Remote Management System, specifically RMS Connect or RMS VPN HUB features, which allow you to access devices connected to Teltonika routers and gateways without the need of public IP: 

Best regards,


by anonymous

I made IPsec tunnel between routers and I successfully ping PC1 from Router2 and PC2 from Router1. Problem is I can not ping PC2 from PC1 and vice versa through the tunnel. In fact I can not ping anything on WAN side from the PC1 and PC2.