@Victorlin In theory if your main router has a public IP address a DMZ in your main router to 192.168.0.2 should give you an access to the C7 VPN server.

@newbie199 This should suffice if you want to use a custom DNS instead of the ISP provided:

@helplessuser_1 These requests are intended to check if the router has an internet access. You can't avoid these checks as the device is in router mode and that's implemented into its FW.

@Sajith Check your C6U WAN (Internet) port IP address and make sure that is public IP address so the DMZ could work for you. It should not be in these ranges: 10.0.0.0 – 10.255.255.255 172.16.0.0 –...

@aboninski In AP mode DHCP should be disabled (refer the guide I posted). Leave them to get their IP address dynamically (by your ISP modem/router DHCP server). Test the internet connectivity and...

@aboninski The problem comes from your ISP modem/router configuration - the subnet mask 255.255.192.0 on your router (A) WAN interface. Your ISP device already does NAT so the configuration I...