I would like to use my Fritzbox 7362SL as a travel router.
When traveling, I would like to connect the Fritzbox then to LAN connections (hotel, vacation home, etc.). The Fritzbox should then build a VPN tunnel to home and route all clients that are connected to the Fritzbox through it.
I have installed OpenWRT 22.03.4 on the Fritzbox. As guide I wanted to follow the dumpap guide, but there the WAN port of the AP router (i.e. my Fritzbox) is not used. Instead, the LAN port of the AP router is given a fixed IP in the subnet of the main router. But this does not work for me, because I do not know the subnet of the main router before.
According to my understanding the IP of the AP router should be variable. So I configured the WAN port of the Fritzbox as DHCP client and connected it to my home network. But this does not work. I then get no Internet via the Fritzbox and in OpenWRT it says for the WAN: Network device is not present.
Can you please help me? How do I proceed?