How can you change Network settings (IP Address, DNS, WINS, Host Name) with code in C#

Question

I am developing a wizard for a machine that is to be used as a backup of other machines. When it replaces an existing machine, it needs to set its IP address, DNS, WINS, and host name to match the machine being replaced.

Is there a library in .net (C#) which allows me to do this programatically?

There are multiple NICs, each which need to be set individually.

EDIT

Thank you TimothyP for your example. It got me moving on the right track and the quick reply was awesome.

Thanks balexandre. Your code is perfect. I was in a rush and had already adapted the example TimothyP linked to, but I would have loved to have had your code sooner.

I've also developed a routine using similar techniques for changing the computer name. I'll post it in the future so subscribe to this questions RSS feed if you want to be informed of the update. I may get it up later today or on Monday after a bit of cleanup.

Answer 1

Just made this in a few minutes:

using System;
using System.Management;

namespace WindowsFormsApplication_CS
{
  class NetworkManagement
  {
    public void setIP(string ip_address, string subnet_mask)
    {
      ManagementClass objMC =
        new ManagementClass("Win32_NetworkAdapterConfiguration");
      ManagementObjectCollection objMOC = objMC.GetInstances();

      foreach (ManagementObject objMO in objMOC)
      {
        if ((bool)objMO["IPEnabled"])
        {
          ManagementBaseObject setIP;
          ManagementBaseObject newIP =
            objMO.GetMethodParameters("EnableStatic");

          newIP["IPAddress"] = new string[] { ip_address };
          newIP["SubnetMask"] = new string[] { subnet_mask };

          setIP = objMO.InvokeMethod("EnableStatic", newIP, null);
        }
      }
    }

    public void setGateway(string gateway)
    {
      ManagementClass objMC = new ManagementClass("Win32_NetworkAdapterConfiguration");
      ManagementObjectCollection objMOC = objMC.GetInstances();

      foreach (ManagementObject objMO in objMOC)
      {
        if ((bool)objMO["IPEnabled"])
        {
          ManagementBaseObject setGateway;
          ManagementBaseObject newGateway =
            objMO.GetMethodParameters("SetGateways");

          newGateway["DefaultIPGateway"] = new string[] { gateway };
          newGateway["GatewayCostMetric"] = new int[] { 1 };

          setGateway = objMO.InvokeMethod("SetGateways", newGateway, null);
        }
      }
    }

    public void setDNS(string NIC, string DNS)
    {
      ManagementClass objMC = new ManagementClass("Win32_NetworkAdapterConfiguration");
      ManagementObjectCollection objMOC = objMC.GetInstances();

      foreach (ManagementObject objMO in objMOC)
      {
        if ((bool)objMO["IPEnabled"])
        {
          // if you are using the System.Net.NetworkInformation.NetworkInterface
          // you'll need to change this line to
          // if (objMO["Caption"].ToString().Contains(NIC))
          // and pass in the Description property instead of the name 
          if (objMO["Caption"].Equals(NIC))
          {
            ManagementBaseObject newDNS =
              objMO.GetMethodParameters("SetDNSServerSearchOrder");
            newDNS["DNSServerSearchOrder"] = DNS.Split(',');
            ManagementBaseObject setDNS =
              objMO.InvokeMethod("SetDNSServerSearchOrder", newDNS, null);
          }
        }
      }
    }

    public void setWINS(string NIC, string priWINS, string secWINS)
    {
      ManagementClass objMC = new ManagementClass("Win32_NetworkAdapterConfiguration");
      ManagementObjectCollection objMOC = objMC.GetInstances();

      foreach (ManagementObject objMO in objMOC)
      {
        if ((bool)objMO["IPEnabled"])
        {
          if (objMO["Caption"].Equals(NIC))
          {
            ManagementBaseObject setWINS;
            ManagementBaseObject wins =
            objMO.GetMethodParameters("SetWINSServer");
            wins.SetPropertyValue("WINSPrimaryServer", priWINS);
            wins.SetPropertyValue("WINSSecondaryServer", secWINS);

            setWINS = objMO.InvokeMethod("SetWINSServer", wins, null);
          }
        }
      }
    } 
  }
}

Answer 2

Refactored the code from balexandre a little so objects gets disposed and the new language features of C# 3.5+ are used (Linq, var, etc). Also renamed the variables to more meaningful names. I also merged some of the functions to be able to do more configuration with less WMI interaction. I removed the WINS code as I don't need to configure WINS anymore. Feel free to add the WINS code if you need it.

For the case anybody likes to use the refactored/modernized code I put it back into the community here.

/// <summary>
/// Helper class to set networking configuration like IP address, DNS servers, etc.
/// </summary>
public class NetworkConfigurator
{
    /// <summary>
    /// Set's a new IP Address and it's Submask of the local machine
    /// </summary>
    /// <param name="ipAddress">The IP Address</param>
    /// <param name="subnetMask">The Submask IP Address</param>
    /// <param name="gateway">The gateway.</param>
    /// <remarks>Requires a reference to the System.Management namespace</remarks>
    public void SetIP(string ipAddress, string subnetMask, string gateway)
    {
        using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
        {
            using (var networkConfigs = networkConfigMng.GetInstances())
            {
                foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(managementObject => (bool)managementObject["IPEnabled"]))
                {
                    using (var newIP = managementObject.GetMethodParameters("EnableStatic"))
                    {
                        // Set new IP address and subnet if needed
                        if ((!String.IsNullOrEmpty(ipAddress)) || (!String.IsNullOrEmpty(subnetMask)))
                        {
                            if (!String.IsNullOrEmpty(ipAddress))
                            {
                                newIP["IPAddress"] = new[] { ipAddress };
                            }

                            if (!String.IsNullOrEmpty(subnetMask))
                            {
                                newIP["SubnetMask"] = new[] { subnetMask };
                            }

                            managementObject.InvokeMethod("EnableStatic", newIP, null);
                        }

                        // Set mew gateway if needed
                        if (!String.IsNullOrEmpty(gateway))
                        {
                            using (var newGateway = managementObject.GetMethodParameters("SetGateways"))
                            {
                                newGateway["DefaultIPGateway"] = new[] { gateway };
                                newGateway["GatewayCostMetric"] = new[] { 1 };
                                managementObject.InvokeMethod("SetGateways", newGateway, null);
                            }
                        }
                    }
                }
            }
        }
    }

    /// <summary>
    /// Set's the DNS Server of the local machine
    /// </summary>
    /// <param name="nic">NIC address</param>
    /// <param name="dnsServers">Comma seperated list of DNS server addresses</param>
    /// <remarks>Requires a reference to the System.Management namespace</remarks>
    public void SetNameservers(string nic, string dnsServers)
    {
        using (var networkConfigMng = new ManagementClass("Win32_NetworkAdapterConfiguration"))
        {
            using (var networkConfigs = networkConfigMng.GetInstances())
            {
                foreach (var managementObject in networkConfigs.Cast<ManagementObject>().Where(objMO => (bool)objMO["IPEnabled"] && objMO["Caption"].Equals(nic)))
                {
                    using (var newDNS = managementObject.GetMethodParameters("SetDNSServerSearchOrder"))
                    {
                        newDNS["DNSServerSearchOrder"] = dnsServers.Split(',');
                        managementObject.InvokeMethod("SetDNSServerSearchOrder", newDNS, null);
                    }
                }
            }
        }
    }
}

Answer 3

I like the WMILinq solution. While not exactly the solution to your problem, find below a taste of it :

using (WmiContext context = new WmiContext(@"\\.")) {

  context.ManagementScope.Options.Impersonation = ImpersonationLevel.Impersonate;
  context.Log = Console.Out;

  var dnss = from nic in context.Source<Win32_NetworkAdapterConfiguration>()
          where nic.IPEnabled
          select nic;

  var ips = from s in dnss.SelectMany(dns => dns.DNSServerSearchOrder)
          select IPAddress.Parse(s);
}  

http://www.codeplex.com/linq2wmi

Answer 4

A far more clear solution is to use the command netsh to change the IP (or setting it back to DHCP)

netsh interface ip set address "Local Area Connection" static 192.168.0.10 255.255.255.0

Where "Local Area Connection" is the name of the network adapter. You could find it in the windows Network Connections, sometimes it is simply named "Ethernet".

Here are two methods to set the IP and also to set the IP back to DHCP "Obtain an IP address automatically"

public bool SetIP(string networkInterfaceName, string ipAddress, string subnetMask, string gateway = null)
{
    var networkInterface = NetworkInterface.GetAllNetworkInterfaces().FirstOrDefault(nw => nw.Name == networkInterfaceName);
    var ipProperties = networkInterface.GetIPProperties();
    var ipInfo = ipProperties.UnicastAddresses.FirstOrDefault(ip => ip.Address.AddressFamily == AddressFamily.InterNetwork);
    var currentIPaddress = ipInfo.Address.ToString();
    var currentSubnetMask = ipInfo.IPv4Mask.ToString();
    var isDHCPenabled = ipProperties.GetIPv4Properties().IsDhcpEnabled;

    if (!isDHCPenabled && currentIPaddress == ipAddress && currentSubnetMask == subnetMask)
        return true;    // no change necessary

    var process = new Process
    {
        StartInfo = new ProcessStartInfo("netsh", $"interface ip set address \"{networkInterfaceName}\" static {ipAddress} {subnetMask}" + (string.IsNullOrWhiteSpace(gateway) ? "" : $"{gateway} 1")) { Verb = "runas" }
    };
    process.Start();
    var successful = process.ExitCode == 0;
    process.Dispose();
    return successful;
}

public bool SetDHCP(string networkInterfaceName)
{
    var networkInterface = NetworkInterface.GetAllNetworkInterfaces().FirstOrDefault(nw => nw.Name == networkInterfaceName);
    var ipProperties = networkInterface.GetIPProperties();
    var isDHCPenabled = ipProperties.GetIPv4Properties().IsDhcpEnabled;

    if (isDHCPenabled)
        return true;    // no change necessary

    var process = new Process
    {
        StartInfo = new ProcessStartInfo("netsh", $"interface ip set address \"{networkInterfaceName}\" dhcp") { Verb = "runas" }
    };
    process.Start();
    var successful = process.ExitCode == 0;
    process.Dispose();
    return successful;
}