If the USB-C to 2.5 Gigabit Ethernet Adapter (ST-AE25M) is not giving you a wired connection, start with the physical connections and the cable, since the USB-C to 2.5 Gigabit Ethernet Adapter is plug-and-play and needs no drivers. It provides a standard Ethernet port that supports 10, 100, 1000, and 2500 Mbps, so it also works fine on slower networks.

How to fix connection problems with the USB-C to 2.5 Gigabit Ethernet Adapter

1. Seat the USB-C connector fully into the USB-C port on your computer or tablet, then try a different USB-C or Thunderbolt port on the same device.
2. Plug one end of your Ethernet cable into a LAN port on your modem or router, and the other end into the Ethernet port on the USB-C to 2.5 Gigabit Ethernet Adapter.
3. Use a Cat 5 cable or higher. An older or damaged cable is a common cause of no connection or slow speeds.
4. Do not install drivers. The USB-C to 2.5 Gigabit Ethernet Adapter is plug-and-play and works with macOS, Windows 10 and 11, ChromeOS, iPadOS, and iOS without any software.
5. Check that your computer sees a new wired connection. On a Mac, open System Settings and go to Network. On Windows, open Device Manager or Network Connections.
6. Unplug the USB-C to 2.5 Gigabit Ethernet Adapter, wait a few seconds, then reconnect it and check again.
7. Confirm your host device is supported. The USB-C to 2.5 Gigabit Ethernet Adapter works with Thunderbolt 3, Thunderbolt 4, USB4, USB-C 3.2 Gen2, and USB-C 3.2 host devices, and it is not compatible with Mac devices released in 2011 or earlier.
8. If you are connecting to a USB-A port, remember that a separate USB-A to USB-C adapter is required and is not included.
9. If the connection works but speeds are below 2.5 Gigabit, check the rest of your setup. Reaching 2.5 Gigabit requires your host device, your internet service provider, and your router or modem to all support Multi-GIG speeds. Below that, the USB-C to 2.5 Gigabit Ethernet Adapter falls back to 10, 100, or 1000 Mbps.
10. Test the USB-C to 2.5 Gigabit Ethernet Adapter on a different computer to confirm whether the issue is the adapter or the host device.