MAC Addresses

See Port Forwarding & Bridged Networking for additional background.

Looking Up MAC Addresses

Each of our virtual machines has associated with it a random string of numbers called its MAC address. Because of the risk of MAC spoofing, these number are secured on DynamicsHJC.

If you are logged into the VirtualBox Machines (vbox) account on DynamicsHJC, you view the file using

cat ~/mac-addresses.txt

or, if you are sitting in front of the monitor, opening the file through Finder. It is stored in the home directory.

If you are not logged into the vbox account, you can obtain the list through SSH:

ssh "cat ~/mac-addresses.txt"

Registering New MAC Addresses

Additional machine names with new MAC addresses can be registered with the university network by following these steps:

  1. Generate a new random MAC address by selecting the virtual machine in VirtualBox, choosing Settings > Network > Advanced, and clicking the blue arrows. Write this number down and press OK. If the virtual machine is configured to use bridged networking (“Attached to: Bridged Adapter”), it will not be able to connect to the CWRU wired network until the remaining steps are completed.

  2. Ask Dr. Chiel to visit (using a different machine) UTech Self-Service Tools, choose Student Device Registration, and enter his CWRU credentials. He should then submit the machine name of the virtual machine (chosen during OS installation and retrievable by typing hostname on the command line) and the new MAC address.

    If Dr. Chiel is unavailable, you can start this process yourself and later submit a request to to transfer ownership of the registered machine to him.


    Verify that Student Device Registration works for non-students.

  3. Registration may take several hours to complete. Once done, internet access will be restored to the virtual machine if it is configured for bridged networking. If it is using port forwarding (“Attached to: NAT”), there should have been no interruption of internet access.

  4. Add the new hostname and MAC address to the file /Users/vbox/mac-addresses.txt on DynamicsHJC.