Sometimes you need to make your Linux box look like another at the switch layer (layer 2 btw). This might make your machine look like another to the networking gear, or if you don't want the manufacturer of your network card to be known to other devices on the network segment. The process is really easy if don't need the change to be persistant between reboots.
ifdown eth0
ifconfig eth0 hw ether 00:80:FF:FF:98:F5
ifup eth0
If you need to make the change persistent between reboots you can put these commands in the file:
/etc/rc.local
The commands in rc.local get run each time the system boots.
If you want to play with this you can use the command:
arp -a
This command works on both windows and linux, and will list all the MAC addresses your machine can see on the local network segment. If you want to determine what manufacturer made the network card associated with the MAC addresses you found, you can look them up with the nifty tools found here.
