u/fabiotimewolf

Hi everyone,

I'm trying to understand whether this is a hardware issue or if anyone has experienced something similar with the FRITZ!Box 7690.

My setup is very simple:

• FRITZ!Box 7690 running FRITZ!OS 8.25
• A Gigabit Ethernet PC
• Direct connection (no switches, patch panels or wall sockets)

The strange behavior is:

• LAN2 → 100 Mbps
• LAN3 → 1 Gbps

To rule out other causes, I performed the following tests:

• Same PC
• Same Ethernet cable
• Same FRITZ!Box
• Same configuration
• The only thing I changed was moving the Ethernet cable from LAN2 to LAN3

Results:

• LAN2 always negotiates at 100 Mbps
• LAN3 immediately negotiates at 1 Gbps

Additional information:

• LAN2 is configured in Power Mode (1 Gbit/s), not Green Mode.
• Energy Efficient Ethernet (EEE) is disabled.
• FRITZ!OS is updated to 8.25.
• The connection is direct (no intermediate devices).
• The Ethernet cable has been ruled out since it works at 1 Gbps on LAN3.
• I also visually inspected the LAN2 RJ45 port and I can't see any bent pins, damaged contacts, or any other obvious signs of physical damage.

Has anyone experienced a single LAN port on a FRITZ!Box behaving like this?