Q:

C# - enable / disable DHCP

I'm looking for a way to to enable or disable DHCP using C# on a given network adapter. looking for the easiest solution.
Thank you.

A:

Maybe..
        const string networcCardName = "[00000007] Intel(R) Ethernet Connection I217-LM"; //Example NIC name
        var management = new ManagementClass("Win32_NetworkAdapterConfiguration");
        var moc = management.GetInstances();

        foreach (var o in moc)
        {
            var mo = (ManagementObject) o;
            if (!(bool) mo["IPEnabled"]) continue;
            if (!mo["Caption"].Equals(networcCardName)) continue;

            var ndns = mo.GetMethodParameters("SetDNSServerSearchOrder");
            ndns["DNSServerSearchOrder"] = null;
            var enableDhcp = mo.InvokeMethod("EnableDHCP", null, null);
            var setDns = mo.InvokeMethod("SetDNSServerSearchOrder", ndns, null);
        }

A:

You could use Process to fire off netsh commands to set all the properties in the network dialogs.
eg:
To set a static ipaddress on an adapter 
netsh interface ip set address "Local Area Connection" static 192.168.0.10 255.255.255.0 192.168.0.1 1

To set it to dhcp you'd use
netsh interface ip set address "Local Area Connection" dhcp

To do it from C# would be
Process p = new Process();
ProcessStartInfo psi = new ProcessStartInfo("netsh", "interface ip set address \"Local Area Connection\" static 192.168.0.10 255.255.255.0 192.168.0.1 1");
p.StartInfo = psi;
p.Start();

Setting to static can take a good couple of seconds to complete so if you need to, make sure you wait for the process to exit.

