Public Function ldGetGroupsDistinguishedNames(cnFilter As String, 
                                                  server As String, 
                                                  domain As String, 
                                                  username As String, 
                                                  password As String) As List(Of String)
                                                  
        Dim results As New List(Of String)

        If String.IsNullOrEmpty(cnFilter) OrElse String.IsNullOrEmpty(server) OrElse String.IsNullOrEmpty(domain) Then
            Throw New ArgumentException("CN filter, server and domain must not be empty.")
        End If

        ' Setup LDAP connection and credentials
        Dim ldapCon As New LdapConnection(server)
        Dim networkCreds As New NetworkCredential(username, password, domain)
        ldapCon.AuthType = AuthType.Negotiate

        ' Bind to the LDAP server
        Try
            ldapCon.Bind(networkCreds)
        Catch ex As Exception
            Throw New ArgumentException("LDAP bind error: " & ex.Message)
            Return results
        End Try

        ' Build the LDAP query filter
        Dim queryString As String = "(&(objectClass=group)(cn=" & cnFilter & "))"

        ' Empty array to retrieve all attributes (or specify attributes to load)
        Dim emptyArray As String() = {}

        ' Build the search request
        Dim searchRequest As New SearchRequest(domain, queryString, Protocols.SearchScope.Subtree, emptyArray)

        ' Issue the search request
        Try
            Dim searchResponse As SearchResponse = CType(ldapCon.SendRequest(searchRequest), SearchResponse)

            For Each entry As SearchResultEntry In searchResponse.Entries
                If entry.Attributes.Contains("distinguishedName") Then
                    Dim dn As String = entry.Attributes("distinguishedName")(0).ToString()
                    results.Add(dn)
                End If
            Next
        Catch ex As Exception
            Throw New Exception("LDAP search error: " & ex.Message & vbCrLf & "Query: " & queryString & vbCrLf)
        End Try

        Return results
    End Function

    Public Function ldGetGroupsDistinguishedNames(cnFilter As String, 
                                                  server As String, 
                                                  domain As String, 
                                                  username As String, 
                                                  password As String) As List(Of String)
                                                  
        Dim results As New List(Of String)

        If String.IsNullOrEmpty(cnFilter) OrElse String.IsNullOrEmpty(server) OrElse String.IsNullOrEmpty(domain) Then
            Throw New ArgumentException("CN filter, server and domain must not be empty.")
        End If

        ' Setup LDAP connection and credentials
        Dim ldapCon As New LdapConnection(server)
        Dim networkCreds As New NetworkCredential(username, password, domain)
        ldapCon.AuthType = AuthType.Negotiate

        ' Bind to the LDAP server
        Try
            ldapCon.Bind(networkCreds)
        Catch ex As Exception
            Throw New ArgumentException("LDAP bind error: " & ex.Message)
            Return results
        End Try

        ' Build the LDAP query filter
        Dim queryString As String = "(&(objectClass=group)(cn=" & cnFilter & "))"

        ' Empty array to retrieve all attributes (or specify attributes to load)
        Dim emptyArray As String() = {}

        ' Build the search request
        Dim searchRequest As New SearchRequest(domain, queryString, Protocols.SearchScope.Subtree, emptyArray)

        ' Issue the search request
        Try
            Dim searchResponse As SearchResponse = CType(ldapCon.SendRequest(searchRequest), SearchResponse)

            For Each entry As SearchResultEntry In searchResponse.Entries
                If entry.Attributes.Contains("distinguishedName") Then
                    Dim dn As String = entry.Attributes("distinguishedName")(0).ToString()
                    results.Add(dn)
                End If
            Next
        Catch ex As Exception
            Throw New Exception("LDAP search error: " & ex.Message & vbCrLf & "Query: " & queryString & vbCrLf)
        End Try

        Return results
    End Function