KDB Systems

Prepar­ing to move DHCP

As part of the project I have to move the DHCP server from the SBS server to a new server. With Win­dows Server 2008 R2 Enter­prise you get what is called one plus four licens­ing. You can install it on phys­i­cal hard­ware. That’s the one license. If this instal­la­tion is only used as a Hyper-V par­ent you can then install four child par­ti­tions with the same license. So far I’ve used two of these licenses, one for the domain con­troller and one for the future Exchange server. I want to run a Ter­mi­nal Server for the third license. This leaves me with one spare license. I plan to exper­i­ment with Direct Access so I’ll prob­a­bly need the last license for that. Long story short, DHCP would have to go on one of the exist­ing servers. I decided to put it on the domain con­troller. Dur­ing the changeover I’ll be run­ning DHCP on the SBS server and the new domain con­troller. The rea­son for this is one or the other may be down for a while when mak­ing changes. This isn’t nor­mally a big deal as long as none of the exist­ing leases expire or no new com­put­ers get con­nected to the net­work. My prob­lem is I have many dif­fer­ent com­put­ers com­ing and going. I may have cus­tomer com­put­ers I’m work­ing on that would need a new lease. This means two DHCP servers. I installed The DHCP server role on the new domain con­troller, con­fig­ured both the exist­ing DHCP on the SBS server and the new DHCP with the same scope but dif­fer­ent exclu­sions so they wouldn’t be try­ing to give out the same addresses. Once fin­ished I autho­rised the new DHCP server in Active Direc­tory and logged off. The next morn­ing there was a sur­prise wait­ing for me in the daily SBS report. One ser­vice was not run­ning. I logged on to the SBS server and saw that DHCP was not run­ning. I’d for­got­ten one of SBS’s quirks. If another DHCP server is run­ning it will shut down its own DHCP server. A quick Bing/Google search found the reg­istry change and all was well with DHCP run­ning on both servers. One more check­point done on the migra­tion from SBS 2003 to Server 2008 R2 and Exchange 2010.

SBS 2003 to Win­dows Server 2008 R2 and Exchange 2010 Migra­tion (Part 1)
SBS 2003 to Win­dows Server 2008 R2 and Exchange 2010 Migra­tion (Part 2)
SBS 2003 to Win­dows Server 2008 R2 and Exchange 2010 Migra­tion (Part 3)
SBS 2003 to Win­dows Server 2008 R2 and Exchange 2010 Migra­tion (Part 4)