using System;
using System.IO;
using System.DirectoryServices;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Collections;

namespace System_DirectoryServices_DirectoryEntry_ConfigIIS
{
  class Program
  {
    static void Main(string[] args)
    {


...
SetIPSecurityProperty("IIS://localhost/W3SVC", "DomainDeny", "domain.microsoft.com");


...
}


...
static void SetIPSecurityProperty(string metabasePath, string member, string item)
{
    //  metabasePath is of the form "IIS://<servername>/<path>"
    //    for example "IIS://localhost/SMTPSVC/1" 
    //  member is of the form "IPGrant|IPDeny|DomainGrant|DomainDeny"
    //  item is of the form "<ipaddress|domain>", for example, 157.56.236.15 or domain.microsoft.com
    Console.WriteLine("\nEnumerating the IPSecurity property at {0}:", metabasePath);

    try
    {
        if (("IPGrant" != member) && ("IPDeny" != member) && ("DomainGrant" != member) && ("DomainDeny" != member))
        {
            Console.WriteLine(" Failed in SetIPSecurityProperty; second param must be one of IPGrant|IPDeny|DomainGrant|DomainDeny");
        }
        else
        {
            DirectoryEntry path = new DirectoryEntry(metabasePath);
            path.RefreshCache();
            object ipsecObj = path.Invoke("Get", new string[] { "IPSecurity" });
            Type t = ipsecObj.GetType();
            Array data = (Array)t.InvokeMember(member, BindingFlags.GetProperty, null, ipsecObj, null);
            Console.WriteLine(" Old {0} =", member);
            bool exists = false;
            foreach (object dataItem in data)
            {
                Console.WriteLine("  {0}", dataItem.ToString());
                if (dataItem.ToString().StartsWith(item))
                {
                    exists = true;
                }
            }

            if (exists)
            {
                Console.WriteLine(" {0} already exists in {1}", item, member);
            }
            else
            {
                object[] newData = new object[data.Length + 1];
                data.CopyTo(newData, 0);
                newData.SetValue(item, data.Length);
                t.InvokeMember(member, BindingFlags.SetProperty, null, ipsecObj, new object[] { newData });
                path.Invoke("Put", new object[] { "IPSecurity", ipsecObj });
                path.CommitChanges();

                path.RefreshCache();
                ipsecObj = path.Invoke("Get", new string[] { "IPSecurity" });
                data = (Array)t.InvokeMember(member, BindingFlags.GetProperty, null, ipsecObj, null);
                Console.WriteLine(" New {0} =", member);
                foreach (object dataItem in data)
                    Console.WriteLine("  {0}", dataItem.ToString());
                Console.WriteLine(" Done.");
            }
        }
    }
    catch (Exception ex)
    {
        if ("HRESULT 0x80005006" == ex.Message)
            Console.WriteLine(" Property IPSecurity does not exist at {0}", metabasePath);
        else
            Console.WriteLine("Failed in SetIPSecurityProperty with the following exception: \n{0}", ex.Message);
    }
}


...
  }
}

Imports System
Imports System.IO
Imports System.DirectoryServices
Imports System.Reflection
Imports System.Runtime.InteropServices
Imports System.Collections

Module Program

    Sub Main(ByVal args() As String)


...
End Sub


...
End Module