My home network is protected with a VPN client set up on the router. I have acquired a NAS that I have configured to be a VPN server in order to access it from the outside through L2TP protocol (the NAS is connected to the router). It works perfectly with my router VPN deactivated as I just have to connect to my public ISP IP (port forwarding, etc. all set up correctly)
However how to achieve that with the router VPN up ? Using my public IP does not work anymore and I cannot use the VPN IP, obviously.
Edit : For the sake of clarity, the vpn client on the router is set up with a 3rd party vpn provider. Edit 2 : I have disabled the NAT firewall of my VPN provider with no success