LDAPS connection with ASP.Net/C#


I have a connection string for LDAP protocol


which works fine.

But I need to use a LDAPS connection :


which does show up in ldp.exe windows form when I test the connection.

Unfotunately it does not work in the Asp.Net application. I get "Unknown error (0x80005000)".

I am not sure whether LDAPS string is even possible with Asp.Net. I downloaded the source code into LDAPConnection.cs class and was unable to find any valuable information.

asked on Stack Overflow May 26, 2017 by DotNetJ • edited May 26, 2017 by Rom Eh

1 Answer


The method you found that works is indeed using LDAPS:


That's the only way to do it. I do that in one of my existing projects. It doesn't understand "LDAPS://".

If you don't believe me :) fire up Wireshark as you debug. When it connects, you'll see the SSL handshake to your domain controller.

Port 636 is only for LDAPS. Port 389 is the non-SSL port.

If you have more than one domain, you can use port 3269 for the global catalog via SSL.

answered on Stack Overflow May 27, 2017 by Gabriel Luci

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