Have you already checked the port forwarding and DynDNS?
To be able to run WireGuard on a Raspi within the internal network of a downstream router, the WireGuard server needs a private port, let’s say UDP 61111 as an example:
- on IB3 forwarding of port 61111 from IB3 to the IP of the downstream router within the IB3 network
- On own router Forwarding of port 61111 from own router to the IP of the Raspi within the own network
- The DynDNS used is best tracked directly on the Swisscom Internetbox, or otherwise using an external service that does not derive the public IPv4 of the Internet access directly from the WAN interface of your own internal router.
With this setup, my own WireGuard servers (I have 2 of them) continue to work without any problems, even in parallel with the new WireGuard server of the Internet boxes.
Hobby-Nerd ohne wirtschaftliche Abhängigkeiten zur Swisscom