I am running a 6.5 version of Teamcity on a Debian Squeeze server and I use OpenLDAP to authenticate users.
I know I can use LDAPS to be able to use encrypted password authentication, however this has been deprecated by the OpenLDAP developers, see: http://www.openldap.org/faq/data/cache/605.html
I would like to know if there is a way to configure LDAP authentication in Teamcity to use StartTLS on port 389.
I can't find anything about it here: http://confluence.jetbrains.net/display/TCD65/LDAP+Integration Or here: http://therightstuff.de/2009/02/02/How-To-Set-Up-Secure-LDAP-Authentication-With-TeamCity.aspx
I filed a bug report at teamcity's bug tracking system which was assigned to a developer. Indicating this is a feature not yet implemented in teamcity.
Therefore, to answer the question, currently it is not possible to configure LDAP authentication in Teamcity using StartTLS on port 389.