I use NAT in my firewall to remote desktop into my work computer from home (or anywhere). My old work computer was set to use DHCP, but as long as I logged in at least every 90 days, it kept the same IP address so it always worked fine. My new computer has an NVIDEA nForce Networking Controller (it's an HP AMD Opteron Dual Core). I noticed that my IP address kept changing when I rebooted, so I made a DHCP Reservation for it. That didn't work either. That's when I realized that every time I reboot my MAC address changes (back and forth between two different ones). It actually reverses the 2-digit combinations (e.g. 12-34-56-78-9A becomes 9A-78-56-34-12). I am getting the MAC address by going to DOS and typing IPCONFIG -ALL.
Any idea why the MAC address would change each reboot? I only have one controller (and certainly only one network cable attached).