One of the biggest improvements to Windows Server 2012 is the (almost) all encompassing Server Manager. From any 2012 server you can now manage any other 2012 server through WinRM - but if you add a 2008 or 2008 R2 server to Server Manager, you will get a manageability warning of “Online – Verify WinRM 3.0 service is installed, running, and required firewall ports are open“.
To get this working, there are 3 main steps to perform:
Install Windows Management Framework 3.0,
Allow remote server management through WinRM (preferred method is via Group Policy),
Create firewall rules.
1. Install Windows Management Framework 3.0
Go and get the appropriate .msu from here: http://www.microsoft.com/en-us/download/details.aspx?id=34595
Windows Server 2008 R2 SP1
WINDOWS6.1-KB2506143-x64.MSU
Windows Server 2008 SP2
64-bit versions: WINDOWS6.0-KB2506146-x64.MSU
32-bit versions: WINDOWS6.0-KB2506146-x86.MSU
As you can see, there are some slight caveats. 2008 R2 requires SP1 while 2008 requires SP2 to be installed.
2. Allow remote server management through WinRM
There are 2 ways you can do this. I would recommend use Group Policy wherever possible, so go to:
Computer Configuration > Policies > Administrative Templates > Windows Components > Windows Remote Management (WinRM) > WinRM Service > Allow remote server management through WinRM
Set it to enabled and if you want it to listen on all addresses, put a * in IPv4 and IPv6 filter boxes.
Alternatively, you can run the command “winrm quickconfig” to enable remote access
3. Create firewall rules
Do this again through Group Policy, allowing port 5985.
