How do I fix an Invalid MAC Address error?

By Arunkumar posted Jun 30, 2014 08:50 PM


Product and Software: This article applies to all ECS product and software versions, with special instructions based on versions earlier or later than 3.1.9.x.


When an NAC appliance cannot recognize new client-end equipment, the appliance generates an Invalid MAC Address error.

To correct this problem, update the vendor codes based on the version of NAC software you are running:

  • Version 3.1.9.x or later
  • Earlier than version 3.1.9.x

Code Version Later than 3.1.9x

Vendor codes update automatically by running the Auto-Definition Synchronizer from the Scheduler view.

However, if the synchronizer fails to run, or does not perform a complete update (for example, a new NIC card is not identified and a client scan creates a MAC address error), follow the manual process for software versions earlier than version 3.1.9.x.

Since Version 4.0, you can add a vendor code from the Admin UI. If you are using the Auto-Definition Synchronizer scheduled task to update vendor codes, they will show up in the Vendor Code Management view.


Code Version earlier than 3.1.9.x

Create a file containing the new MAC information and put it in the proper directory as follows:

1) Determine the first three octets of the Client MAC address (such as "00-19-D2" in MAC address 00-19-D2-12-32-5D):

  • Windows: Run > ipconfig
  • Linux: Run ifconfig or Run > ip addr
  • MAC OS-X: Go to System Information > Network Properties.

2) Log into the NAC Control Server.

3) Go to the ‘/bsc/campusMgr/master_loader/vendorCodes’ directory.

4) Create a new file in this directory and add:

00:19:D2 = <vendor name>

5) When you save the file, the NAC server detects the new file and reads it, adding the new vendor code to the NAC server.