Following Setup:
Site A)
Cable-Modem in Router-Mode (1 Public-IP)
192.168.12.0/24
connected to OpnSense-Box
WAN: 192.168.12.10 (DMZ of Cable-Modem-Router)
LAN: 10.11.20.0/24
Site B)
LTE-Modem in Router-Mode (1 Public-IP)
192.168.95.0/24
connected to OpnSense-Box
WAN: 192.168.95.10 (DMZ of Cable-Modem-Router)
LAN: 10.95.0.0/24
I can establish the tunnel and access the webinterface of the remote opnsense box but cant access websites on the remote network. however, I can ping the hosts on the remote network and even login via ssh.