LDAPS: Using .NET 4.7.2 System.DirectoryServices.dll - vb.net

Question

I am trying to update my code to get user information from an AD that must use LDAPS calls, not LDAP.
Currently we are using the System.DirectoryServices.dll but I cannot find a way to hit the AD using LDAPS, only LDAP.
Here is how we are defining our entry and searcher objects.
'''
If (ADactive) Then
Dim Entry As New System.DirectoryServices.DirectoryEntry(ADFullPath, Username, Password)
Dim Searcher As New System.DirectoryServices.DirectorySearcher(Entry)
Searcher.SearchScope = DirectoryServices.SearchScope.Subtree
Try
Dim Results As System.DirectoryServices.SearchResult = Searcher.FindOne
Success = Not (Results Is Nothing)
rtn_error = ""
Catch ex As Exception
Success = False
rtn_error = ex.Message
End Try
ADUserName = Username
ADPassword = Password
End If
Return Success
'''
I've verified this code works to hit our AD and I can login using my credentials. Our ADFullPath is
LDAP://XXXXXX
Where the "XXXXX" is my AD server.
Are there different properties to my searcher object that I need to set to enable LDAPS?

Answer 1

You need to specify the LDAPS port (636) in your LDAP path, like this:
LDAP://XXXXXX:636
That's all.
However, all the same rules for SSL apply here. This will only work if:
The domain name on the SSL certificate matches the domain name you're using. So if you use LDAP://example.com:636, then the cert must be issued to (or have a Subject Alternative Name of) example.com.
The certificate is issued by an authority that the client computer trusts. If the cert is self-signed, it will fail.