Connecting a DrayTek Vigor 3900 to Active Directory with SSL LDAP

How do I connect a DrayTek Vigor 3900 to Active Directory to achieve user authentication from certain OUs in AD?

I just keep receiving the message: Can't contact LDAP server (x.x.x.x) whether I use 389 or 636 even though the IP address is an internal one???

Here is what I am entering - I do not know what the 'Common Name Identifier' should be here:

The CN should be as follows:



the regular DN= something like 'CN=LDAPaccount,OU=Support,DC=domain,DC=local'

Which is effectively the path to the username with

DC as the domain and suffix
OU as the organisational units, in order, and
DN as the object name such as the username, but use the user name found with 'DSQuery user' when entered into a command prompt and make a note of the whole path, even better, copy and paste it in.

The DC,OU,CN etc. need to be capitalised on a DrayTek.