How to get the base radio MAC while staging Aruba APs

 When staging/priming APs for deployment, some folks do it ahead of the actual cutover/go-live date so that a cutover runs smoothly.

APs that are staged are booted up on a bench controller, labeled, named, and joined to a controller to verify its operation and burn them in, so-to-speak.  They are placed back in boxes and handed over to low voltage Contractors who install and patch them, and they should headlessly come online.

After all, not all APs can be easily accessed during a go-live, some are in hard to reach spaces, where man lifts may be needed, ICU patient rooms in hospitals, clean rooms where technicians may not wander in at any moment to work on an AP that's having problems.

Priming APs helps eliminate some of the issues come go-live.

Communication badges, such as Vocera system, need the base radio mac address and the AP's hostname, depending on how the system is configured.  If you would like to hand over the AP names and base radio macs of the APs to the Vocera Administrators, this is how it might be accomplished.  This is a rudimentary way of getting the information without having the AP powered up and online, since the mac address is on a label on the access point.

If I were to do this for thousands of access points (and that is my goal) I would like to build a macro enabled Excel spreadsheet and scan the mac address barcode on the physical AP into a spreadsheet and have a macro do the math for me to output the base radio mac.

Credits:  Thanks to @CaNerdIan for the pointers, and to this fella on the Airheads blog. 

By AnandKumar Sukumar   How is the BSSID derived from the Access Point ethernet MAC address? (arubanetworks.com)

First, we scan the mac address from the label.

We all agree the Wired MAC Address is  d0:d3:e0:c1:97:48

Take the last five of the MAC, which is 1:97:48, and remove the colons.

19748

Use this website to convert the hex (19748) to binary:

Take the output,  00011001011101001000, and tack on four zeros.

000110010111010010000000

Now XOR the first four with 1000

000110010111010010000000

XOR

1000

--------------------

100110010111010010000000

If you have forgotten all that math, you can see it right here:

Now we have to convert the sum of that binary XOR back to binary.  (I used this website)

Now, we scroll back up to the top and look at the OUI of the wired mac, which is d0:d3:e0.

We have to put the mac address together, so we combine d0:d3:e0 with 997480, to get d0:d3:e0:99:74:80

How do we know its right, though?

We can look at the controller and see it:

There you have it.  The base radio mac address can be derived from the wired mac address.  I must admit that I didn't think this was possible, as the mac addresses did not look even remotely related to one another.

The real solution, moving forward, would be to have some sort of spreadsheet that the mac could be scanned in, and have a macro do all of this math for us and output a column with the AP hostname and base radio mac.

If anyone has done this, please feel free to share with the community.