Occasionally machines will pull the same IP address, DHCP can easily resolve this, but recently I came across two machines that always pulled the same IP address. Since they were on their own VLAN, I moved them to another VLAN to see if that would resolve the issue.  It did not resolve the issue, in fact they now both pulled the same IP again, but this IP was in the new subnet.

After digging into a little bit, I realized they actually both had the same MAC address. These machines were shipped to us from another company, but I was able to obtain the administrator password for one of the machines and found that they had manually configured the MAC addresses to be the same. I change the last digit on the one device and both machine obtained their own IP. So, if you have this situation, simply go into the properties of the NIC and choose configure. It is under the section where you would change flow control, etc.

We called the company, and apparently they did this to get around a licensing issue, still find it hard to believe they would even think that would work.

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