detect if machine is online or offline using WMI and C#

Question

I use vs2008, winxp, in LAN network with Win2003 servers.

I want a application installed in winxp for detect if win2003 machines is online or offline , and if offline wh

Answer 1

I would go for the .NET System.Net.NetworkInformation.Ping, because it is quite flexible, you have the possibility of doing it asynchronously and I find it more intuitive than WMI (I have used both and use WMI only if I need to get more info from the remote machine than just the ping). But this is just a personal opinion.

Answer 2

Not sure exactly what the question is for, but for what it's worth, I have a test framework that runs tests on VMs and needs to reboot them. After rebooting the box (via WMI) I wait for a ping fail, then a ping success (using System.Net.NetworkInformation.Ping as mentioned by others) then I need to wait until Windows is ready:

    private const int RpcServerUnavailable = unchecked((int)0x800706BA);

    private const int RpcCallCancelled = unchecked((int)0x80010002);

    public bool WindowsUp(string hostName)
    {
        string adsiPath = string.Format(@"\\{0}\root\cimv2", hostName);
        ManagementScope scope = new ManagementScope(adsiPath);
        ManagementPath osPath = new ManagementPath("Win32_OperatingSystem");
        ManagementClass os = new ManagementClass(scope, osPath, null);

        ManagementObjectCollection instances = null;
        try
        {
            instances = os.GetInstances();
            return true;
        }
        catch (COMException exception)
        {
            if (exception.ErrorCode == RpcServerUnavailable || exception.ErrorCode == RpcCallCancelled)
            {
                return false;
            }
            throw;
        }
        finally
        {
            if (instances != null)
            {
                instances.Dispose();
                instances = null;
            }
        }
    }

It's a little naive, but it works :)

Answer 3

If the machines honor ICMP echo requests, you can use the Ping class instead of WMI.