Campus Network (Windows and macOS) - Find the MAC Address of an Ethernet Adapter

This document describes how to find the MAC address of an Ethernet adapter.

What are Ethernet adapters

Computers without Ethernet ports use Ethernet adapters to create a wired network connection. These adapters usually connect to the computer's USB or Thunderbolt ports.

You must register the MAC address of the Ethernet adapter you are using to connect your computer to the campus network. Laptops with a built-in Ethernet port must register the MAC address of the laptop itself. See UWNet - Register a Device Without a Browser to register your computer or Ethernet adapter.

The laptop will have its own MAC for wireless connections, but will use the MAC of the adapter for all wired connections.

Windows

  1. With an Ethernet cable plugged into your data jack, connect your Ethernet adapter to the other end of the cable, then plug the Ethernet adapter into one of the laptop's USB ports.

  2. Open your Windows start menu, then type cmd in the search bar and press Enter to open Command Prompt.

  3. In Command Prompt, type ipconfig /all.

  4. Information for the Ethernet Adapter will be found under the heading Ethernet adapter.
    The Physical Address corresponds to the MAC address. This is the address that will need to be registered for housing network connections. See 

macOS 

macOS 15 Sequoia

  1. Plug one end of an Ethernet cable into your wall data jack.
  2. Plug the other end into your Ethernet adapter.
  3. Plug the Ethernet adapter into your computer's USB or Thunderbolt ports.
  4. Click the Apple Menu in the top-left corner.
  5. Click System Settings, then click Network.
  6. Find the network connection with the adapter manufacturer's name or the type of adapter that you're using.
    • Note: Ethernet connections on macOS will usually use the <···> symbol.

      macOS Network tab with Ethernet option

  7. Click Details, then click the Hardware tab.
  8. The address is listed next to MAC Address.

For more information, see Apple's Mac User Guide.

OS X and OS 10.5

  1. With an Ethernet cable plugged into your data jack, connect your Ethernet adapter to the other end of the cable, then plug the Ethernet adapter into one of the laptop's USB or Thunderbolt ports, depending on which type of adapter you are using.
  2. In your Mac's menu bar, click the Apple icon and select System Preferences (or open System Preferences from the dock).

    System Preferences

  3. Select the Network applet from the System Preferences window.
  4. In the Network window, network interfaces are listed on the left-hand side. Select Built-in Ethernet (or just Ethernet).
  5. Click Advanced in the lower right-hand corner of the window.

    Advanced

  1. For OS X 10.8 or 10.9, select the Hardware tab; the MAC address will be listed there.For other OS x, select the Ethernet tab; the MAC address is listed as the Ethernet ID. 

Note: The name of the network interface will depend on what type of adapter you are using, but should contain the word "Ethernet"; for example, a Thunderbolt adapter may be listed under the name "Thunderbolt Ethernet." If you have more than two interfaces listed for Ethernet and are unsure which is the correct one, look for the entry that has the Link Status set to Active (excluding the "WiFi" interface.)

Network Utility


Keywords:
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Doc ID:
76293
Owned by:
Help Desk KB Team in DoIT Help Desk
Created:
2017-09-01
Updated:
2025-06-03
Sites:
DoIT Help Desk, UW Housing