WARNING: Portal for ArcGIS cannot connect to Active Directory LDAP server at ldaps

02-18-2021 06:54 AM
Regular Contributor

 We use Active Directory authentication (not using LDAP). There are two errors in sequence; see below.


  • The only other post I've found related to this involves IWA.
  • I have been assured by our IT provider that all Domain Controllers are Global Catalog Servers.
  • We don't have any authentication issues as a result of this, but it is a curious and troubling warning.
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Esri Contributor

Have you tried connecting to the LDAPS port for global catalogs (3269) using another method such as ldp.exe?

Ldp | Microsoft Docs


That may give you some more information about why the connection is failing. With a connection reset error, it is possible the connection is being blocked by or timing-out on a firewall (either internal or external to the domain controller in question). The Active Directory connection does use LDAP to query the AD structure for users/groups, and connections will be made on 3269, 3268, 636, and 389, depending on whether LDAPS is configured with a proper certificate and the binding options set within group policy.