Locked out of a Windows Server 2008 headless server by mistakenly switching Network Discovery to off

headlesswindows-server-2008

We have a Windows Server 2008 R2 machine that is connected to our LAN.
We inherited this machine, meaning that we didn't set it up ourselves and may not be aware of everything about it. However we know that W2k8 is installed as a VMware guest.

This machine doesn't have a video card and doesn't allow to plug a keyboard or a mouse, additionally its USB ports have been disabled, it is thus a headless server (of course, it has a CD/DVD reader.)
All this means that we always connect via the Ethernet port (using Remote Desktop Connection.)

We mistakenly set Network Discovery to off, and since then this machine appears to be unreachable.
Indeed it doesn't allow RDC anymore and the only thing we can manage to do successfully is to ping it.
Note that this machine is not a domain controller, it's just part of 'Workgroup'. Obviously its name doesn't appear anymore if we do a network scan, but, as I said, we can ping it.

We have tried three things so far to reestablish some form of control over that machine:

  1. Microsoft Management Console (MMC) snap-ins

    This initially was producing a RPC server is unavailable error message. After a while this turned into access denied.

    My guess here is that turning Network Discovery to off disabled some key services required to make the snap-in to work.
    And, after a while, perhaps our attempts started to be perceived by the firewall as attacks, that could be why the error message changed into 'access denied'.

  2. PsTools

    Basically giving the same results as above. First getting the complaints about the RPC server being unavailable and then the 'access denied' one.

  3. Push VNC

    I had never used Push VNC before so I'm not too sure what should be the expected output when all goes well. But it just doesn't seem to "push" it…
    Anyway, maybe it wasn't even intended to push VNC on Windows Server 2008.

So here we are with this "remote server", in fact physically just next to us and reachable by hand, but with no way to get it to "talk" to us…

What steps could we take to get this machine back up and running on our LAN ?

Best Answer

Turning off Network Discovery doesn't disable TS/RDS and doesn't prohibit RPC communications, that I'm aware of. Network Discovery (by and large) is exactly what it sounds like; discovery. Not accessibility or communication but simply discovery. You can generally turn Network Discovery off on any server with any role and still have the server function in that role. My guess is that the server is in a wonky state. I would reboot it and see if that resolves the problem.

How did you "inherit" this machine? Where did you "inherit" it from? What is it's purpose? This sounds like an unsustainable situation. You have a server but don't have full controll of it's hardware and software resources, that's not something I'd allow on my network.

Here's a rundown of Network Discovery with some detail:

http://blogs.technet.com/b/networking/archive/2010/12/06/disabling-network-discovery-network-resources.aspx

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