Error while trying to connect AD using LDAP connection

Question

Trying to use this code to connect the AD

PrincipalContext context = new PrincipalContext(ContextType.Domain, domain)

but i got the error saying:

The LDAP server is unavailable.

Any idea?

Answer 1

The questions is: do you specify our domain as

• "mydomain.com" (DNS format)
• or as "dc=mydomain,dc=com" (AD-style format)

To my surprise, the Domain name must be in DNS format (e.g. "mydomain.com") in order for this to work (and NOT in the usual AD-style format of "dc=mydomain,dc=com").

Answer 2

I had the same problem.

Mine was because the webserver was not on the same domain as the user.

I resolved it by ignoring the error; this then forced an authentication challenge which enabled the user to supply credentials, which I could pick up the correct domain from.