@Clive_A I have created a diagram that makes it a bit clear hopefully. Please note I used a Tp-link 4G router with the public IP. If you need more info please let me know. Best regards, Hans

I have setup an openvpn connection via a modem (Set DMZ to ER7412) to the ER7412-M2 and I can reach the ER7412-M2 config page fine at 172.16.8.1, but i can't reach any of the other hosts with a ping....