How to connect a 10BASE-T device to a FRITZ!Box 7390

Problem

You cannot communicate with a 10BASE-T (10 Mbit/s half-duplex) device connected to one of the Ethernet (LAN) ports of  a FRITZ!Box 7390.

Solution

1. Use a crossover Ethernet cable (not a patch cable) and
2. connect it to port “LAN 1” or “LAN 3”.

See: FRITZ!Box 7390 Service: LAN connection to FRITZ!Box cannot be established