From VEX Wiki

VEXnet MAC Utility

The VEXnet MAC (Media Access Control) Utility allows a network manager to quickly collect a list of the MAC Addresses that are used by VEXnet USB Adapter Keys so they can be authorized by their local IT department. This is especially important if a VEX Robotics Competition event is being held in a school or other venue where an active Wireless Intrusion Prevention System (WIPS) is present, which will shut down or interfere with any unauthorized networks; if one of these systems is present -- make sure you get your MAC Address authorized!

Note: For best performance, it is ALWAYS recommended to disable ALL wireless systems near the area where robots will be operating.

Download the VEXnet MAC Address Utility (v1.0.3, zip 09-20-11)