[Solved] VPN configured on Asus secondary router not working with Nokia G-240W-C primary

Hello everyone. I've been struggling to get an Asus router with NordVPN's configuration profile installed working through a primary Nokia modem/router. The Asus LAN is on a separate subnet and as far as I can tell, everything else is configured OK but I cannot get the VPN to connect. Unfortunately, my ISP makes it impossible to change any LAN or WAN settings on the Nokia nor can I use the Asus (which is a dual DSL/ethernet) router directly. However, the Nokia does give the Asus an IP which its DHCP server duly distributes (I can surf the internet from it without any trouble), but the Nord VPN client refuses to connect. I have ensured that the Nokia allows all packets through, but still no joy. And I am using the VPN's service credentials in case anyone asks. Any suggestions anyone?

This is what it is like with double NAT and VPN. In one configuration it somehow works, in another it does not. For example, NordVPN can compare the public address with the customer's address and reject it. You may need to enable NAT-T on your edge router (which you supposedly can't do) etc.
Overall, OpenVPN over HTTPS is the best at NAT.
You can also ask the operator to switch the terminal to brigde mode - you will get rid of NAT.

However, a question from a different barrel - what do you need this for, because you probably do not believe in this marketing nonsense about greater "security" and do not let yourself be stretched on the money?

Thanks for the suggestions. I may ask the ISP to let me set their equipment to modem-only mode (which is what I think you mean) and try again. As to why I want to use a VPN, well that's easy. I'm a Brit in Poland who wants access to location-sensitive services. NordVPN lets me do that better than most.

It seems either the Linksys router or the DDWRT software it's running wasn't able to resolve my VPN's host name. The problem was finally solved by substituting it with its corresponding IP address....