In case you did not read the Microsoft KB, after applying Update Rollup 4 for Virtual Machine Manager (http://support.microsoft.com/kb/2992024), make sure you manually update all VMM Hyper-V hosts and the VMM Console.
Note: If this component is not updated, virtual machines may not be assigned an IP address for several minutes when the lease expires or after restarting the VM.
Install the updates in the following order:
1. Update Rollup 4 for the Administrator Console
2. Update Rollup 4 for the VMM Server
Let’s start. First, check if the VMM DHCP agent version is up date, as you will need to manually remove it before installing the new one:
From an elevated PowerShell Command Prompt window on the hyper-v host:
PS: >Get-WmiObject -Class win32_product -Filter ‘Name = “Microsoft System Center Virtual Machine Manager DHCP Server (x64)”‘
If result version is earlier than 3.2.7768.0, you will firstly uninstall the old version:
PS: >MsiExec.exe /X <IdentifyingNumber>
Note: <IdentifyingNumber> information should be retrieved from the output of the last command: Get-WmiObject
Locate and copy the file Dhcpextn.msi and run it on each hyper-v host (follow the steps in the wizard)
Note: By default, this is C:\Program Files\Microsoft System Center 2012 R2\Virtual Machine Manager\SwExtn\DHCPExtn.msi.
Double-click the DHCPExtn.msi to start the installation, and then follow the steps in the wizard.
Between these two installations, VMM Server might create one critical error log under the VMMLogs directory. This occurs because AdminConsole shares some DLLs with VMMServer, and version conflict could lead to the logging of the critical failure. To resolve this issue, install both of the updates on the VMM server that you use to start the VMM service.