Yes, it is official, the DHCP Client service can make you pull your hair out. Why? Let me explain. Recently I was involved in setting up several Exchange 2007 SP1 CCR clusters on Windows Server 2008. Several days into the build it was observed one of the clusters was experiencing problems.
Clusters resources would not come online, and fail-over was was not working. After extensive troubleshooting, reviewing logs, and even contacting Microsoft PSS, there was no obvious root cause. Hair was being pulled left and right. In fact, a not so little pile was forming in our windowless conference room.
While reviewing the alerts in the OpsMgr 2007 I observed that the WinHTTP Proxy service could not start because it was dependent on the DHCP Client service which was disabled. I thought this was odd, since the DHCP client should always be running.
The service is very important for domain joined computers, even with static IPs. Why? Because its how the computer performs dynamic DNS updates. And apparently, the cluster service needs it to operate in a healthy manner.
So, if you are experiencing cluster problems, verify the DHCP Client service is set to start automatically. We aren’t sure what disabled the service, but we think a well known anti-virus vendor disabled it when we installed their product. For the customer I recommended a GPO be configured for all Exchange servers to force the service to always be in automatic start mode, in case they had to re-install the A/V solution and it disabled the service, yet again.
