Windows Server DHCP Migration

With Microsoft Windows Server 2003 End Of Live coming up in a few months, a growing number of companies start to examine the migration plans. Most times the DHCP in installed on the 2003 server and has to be migrated.

In case you do not have a complicated DHCP configuration with many reservations or options it may be easier to just install the DHCP role on the new server and configure it from scratch. You should be very careful though when having both servers active because this will result in IP conflicts.

To avoid conflicts I use exclusion ranges. I just exclude let's say half of the IPs from one server and the other half from the other. Even after that, there might be conflicts also because there might be clients that have already got an IP from the range that you excluded on the old server. Thus you should wait for a period of time longer than the lease time.

If you want to migrate the entire DHCP configuration, there is a great article on Technet that describes the process going from 2003 to 2012 R2 with screen shots: http://blogs.technet.com/b/canitpro/archive/2014/11/26/step-by-step-migrating-dhcp-from-windows-server-2003-to-2012-r2.aspx 

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