You connected successfully with the Deutsche Bahn WLAN, but cannot connect to the internet? That’s caused by the fact that the IP address used for the login-page collides with the default network setup of docker.

Workaround

1. Stop all running containers, prune networks and temporarily stop services:

   docker kill $(docker ps -qa)
   docker network prune --force
   sudo systemctl stop docker.service
   sudo systemctl stop docker.socket

2. Open the DB network login website in any browser to accept the terms and conditions.

3. [Optional] Start docker services again:

   sudo systemctl start docker.service
   sudo systemctl start docker.socket

   This is optional, because the service will be started again automatically after a system reboot.
   Perform this step only in case you need docker during the train ride, otherwise you might have to repeat the process after loss of connection.