.Net 可以使用 DirectoryEntry 連接 Active Directory ，假如有個管理後台網頁，此時就可以透過 Active Directory 認證登入後台。

範例程式碼如下：

            string ActiveDirectoryName = "AD網址或者IP";
            string UserName = "帳號";
            string UserPwd = "密碼";
            DirectoryEntry de = new DirectoryEntry("LDAP://" + ActiveDirectoryName, UserName, UserPwd);
            PropertyCollection pc = de.Properties;
            if (pc == null)
            {
                Response.Write("登入失敗");
            }
            else
            {
                Response.Write("登入成功<br><br>");
                //列出相關參數
                foreach (string k in pc.PropertyNames)
                {
                    try
                    {
                        Response.Write(k + " = " + pc[k][0] + "<br>");
                    }
                    catch { }
                }
            }