When carrying out a network security audit it is important to change the MAC address (Media Access Control) of your auditing machine. Changing your MAC address will protect the identity of your machine on the network you are auditing as well as allow you to circumvent MAC filtering and restrictions in place.
Backtrack is my security distrobution of choice and provides an easy way to re-configure your MAC address on the fly:
1. Open Terminal
#ifconfig eth0 down
Note: eth0 can be replaced with any other local interface
3. Change your MAC address using the macchanger application:
#macchanger --mac 00:11:22:33:44:55 eth0
#macchanger -r eth0
This will set a 'random' MAC address on your interface.
4. Re-enable your network interface by typing:
#ifconfig eth0 up
5. Confirm the MAC address is in place by using:
#ifconfig eth0 | grep HWaddr