To set up your router for fiber internet quickly, connect the router to your fiber modem, access the router's settings via a web browser, and input the provided ISP credentials. Make sure to update the firmware, configure Wi-Fi security, and customize your network name for optimal performance. As far as I understand, I need a PPPoE username and password to connect. I never received it from Telekom, as well as Access number (Zugangsnummer). However, setting up a fiber optic connection to your router can seem daunting if you're unfamiliar with the process.