Hi everyone,
I’m troubleshooting an 802.1X issue with a Dell laptop connected through a Dell WD19/WD19S dock.
Topology:
Laptop → Dell Dock → Ethernet → Switch
When I connect the laptop directly to the switch, 802.1X works perfectly and the endpoint authenticates using dot1x.
However, when I connect the same laptop through the Dell dock:
- The switch learns the laptop's actual MAC address
- Forescout sees the laptop correctly
- But authentication is MAB instead of 802.1X
- It looks like the PC's EAPOL/802.1X frames aren't reaching the switch, causing the port to fall back to MAB
The PC's 802.1X configuration is working because it authenticates successfully when connected directly.
Has anyone experienced 802.1X/EAPOL not passing through a Dell WD19/WD19S dock?
Could this be related to MAC passthrough, dock firmware, Realtek Ethernet drivers, or EAPOL pass-through?
What was the fix in your case? Did updating the dock firmware/driver resolve it, or did you have to change a switch/dock/BIOS setting?
Any advice would be appreciated. Thanks