Sorry, I'm not a Zimbra admin, and I may have been confusing in my explanations. The problem occurs with Zimbra acting as an LDAP client against an external LDAP server, performing a bind operation for authenticating users, with the following behaviour: Zimbra against on openldap 2.3.x server, with TLS on port 389: OK Zimbra against on openldap 2.4.x server, on port 636: OK Zimbra against on openldap 2.4.x server, with TLS on port 389: 30s delay
Ok, so what you are saying is: You upgraded your OS to CentOS6 You use external authThe external auth from CentOS6 to your own LDAP server shows a 30 second delay on closing.
That sounds like a bug in Java/JNDI. I did see some 30 second issues with RHEL6, but it was with initiating a connection, not closing it. You can see more about that at <https://stomp.colorado.edu/blog/blog/2011/06/29/on-rhel-6-ssh-dns-firewalls-and-slow-logins/>
I would note that JNDI behavior varies based on startTLS vs SSL on port 636 as well.
--Quanah -- Quanah Gibson-Mount Sr. Member of Technical Staff Zimbra, Inc A Division of VMware, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration