You can test your LDAP connection via the ldap-diag.aspx page. The Connection and Core Attributes sections are loaded from the web.config and ldap.config files. These values are not changeable in this page.
To test your LDAP connection:
Copy the ldap-diag page in the root of your Web application.
Enter your user domain name in the user domain name field and click Load user(s) from domain name.
Enter your user name in the User Friendly Name field and click Load user(s) from friendly name. Instead of looking up the domain name, the tool looks up your actual name.
Enter a group name in the first Group Name field and click Search for Group. The tool searches for a group name with your LDAP settings.
Enter the group name in the second Group Name field and click Load users from group. The tool lists all users in that group.
The results of your queries display in the text box at the bottom of the page.
This tool displays the LDAP password in plain text. This is very useful for debugging purposes, but is a security risk otherwise. After finishing diagnostics, you MUST delete this file.