That connector is the ethernet connection for the docking station. That provides a real ethernet connection on the dock rather than using a USB to ethernet adapter.
Using the NIC that's on the CPU/chipset (I forget which) allows it to use the same MAC regardless of which docking station or adapter is used, simplifying management. It also means that vPro, wake on LAN etc. work - neither are generally a concern for a home user, but both can be desirable in the large enterprise/government situations these are built for.
https://download.lenovo.com/pccbbs/mobiles_pdf/t480s_ug_en.pdf (page 21)
According to the manual, it's a docking station connector.
On my X1 carbon, I have a similar-looking port but it's for the ethernet adapter.
That connector is the ethernet connection for the docking station. That provides a real ethernet connection on the dock rather than using a USB to ethernet adapter.
What is real ethernet but a PCIe to Ethernet adapter?
Using the NIC that's on the CPU/chipset (I forget which) allows it to use the same MAC regardless of which docking station or adapter is used, simplifying management. It also means that vPro, wake on LAN etc. work - neither are generally a concern for a home user, but both can be desirable in the large enterprise/government situations these are built for.
Thanks mate!
Yeah on my 7th gen carbon it’s an Ethernet extension connector.
Probably also works with this? That or the dock.
Edit: clearly redundant with the Ethernet port on the right, which the carbon lacks. So yeah, for the dock.