If you’re running Active Directory, like I said in a previous blog, that’s the majority of readers, you’re almost certainly using LDAPS, the secure version of LDAP. Not just because it’s “best practice,” but because plaintext LDAP over port 389 is a really bad idea, furthermore Microsoft has blocked access when you’re trying to connect to just LDAP on port 389 without any form of security.
While Microsoft has not removed the ability to use LDAP on port 389, recent security hardening features (such as LDAP channel binding and LDAP signing) can be configured to reject simple bind operations that are not signed or encrypted. In practice, many organizations today do not support clear-text LDAP unless it is secured (for example, via LDAPS). That’s why enabling LDAPS and proper security policies is highly recommended.
Unfortunately most environments treat LDAPS like a checkbox: “Yeah, we enabled LDAPS, installed a certificate, moved on.”
And that’s fine… until it isn’t. If your LDAP clients, VPN gateways, firewalls, RADIUS/NPS servers, Linux services, identity proxies, SaaS connectors, security appliances (the list goes on) depend on LDAPS, then what happens when the one Domain Controller you pointed them at suddenly goes offline?
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