An Even Easier DHCP Conflict Solution

In Reader to Reader: "Easy DHCP Conflict Resolution," July 2001, Chris Wong offers an easier solution to an IP address conflict than the remedy Melissa Wise gave in Reader to Reader: "DHCP Conflict," February 2001. I have an even easier solution that resolves a situation in which two clients are trying to grab the same IP address. To implement my solution, your organization must use WINS.

IP address conflicts usually occur when someone turns off a computer with an expired IP address lease. Often, the DHCP server has already issued the IP address to another computer. The first computer requests to use its original IP address, and if the DHCP server doesn't respond quickly, the computer uses the last IP address the DHCP server issued it. Thus, two computers are using the same IP address, which creates a conflict.

To solve the problem, run WINS Administrator on the WINS server. Double-click your WINS server in the WINS Server list. From the drop-down menu, select Mappings, Show Database. Click the Set Filter button, and enter the conflicting IP address. Note the computer's name that the IP address is registered to. Locate the computer that is using the IP address, and shut down the computer. Then, restart the computer that received the IP address conflict error. Finally, restart the computer that you shut down. Both computers will now have a valid IP address.

—Jonathan Reid
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