Why There are some changes in LDAP configuration in CQ5.5 and documetation is still in progress. Before actual documentation comes, Here is few things you should know
Pre requisite Keep http://dev.day.com/docs/en/cq/current/core/administering/ldap_authentication.html on side. I will mention things changed.
No sample_ldap_login.conf under crx-quickstart\server\etc : In fact there is no crx-quickstart\server\etc. You can put your sample_ldap_login.conf any where you want. You can get sample ldap.conf from http://dev.day.com/content/kb/home/cq5/CQ5SystemAdministration/LdapConfig.html or here
2) Once downloaded you can put this file to any location (I prefer /crx-quickstart/conf) and then change your start script to point to this location.
3) I have seen, LDAP not starting because of some wrong configuration in repository.xml. Also attaching sample repository.xml that you can use directly in CQ5.5 / CRX2.3
How to enable logging for LDAP in CQ5.5 / CQ5.6
1) Note that LDAP module is now deployed as OSGI module. You have to follow following step to enable logging for LDAP
 Log into Felix Console: http://<host>:<port>/system/console/configMgr
 From "Factory Configurations", create "Apache Sling Logging Writer Configuration"
[2.1] Set value of "Log File" to "../logs/ldap.log"
[2.2] Click on "Save"
 From "Factory Configurations", create "Apache Sling Logging Logger Configuration"
[3.1] Set value of "Log Level" to "Debug"
[3.2] Set value of "Log File" to "../logs/ldap.log"
[3.3] Add "Logger" => com.day.crx.security.ldap
[3.4] Click on "Save"
Step  is require for log rotation, If you don't want to rotate log then skip that step.
user purge and sync option In CQ5.5 GA release, there is no user purge and sync option. This is moved to JMX. This option is now available as CQ5.5 Update Package 1, That you can download it from package share. To use this option, Please install CQ5.5 Update 1, Start CQ with LDAP enable and then go to Felix JMX console. You would see something like this
Full path in JVM Param I have seen issues with some customer where using relative path for ldap.conf file does not work. Please use complete path of file system instead.
Change in start script: CQ5.5 OOTB has options enabled for jass config. You can use following environment variable to enable LDAP through start script
CQ_JAAS_CONFIG='< Complete Path to LDAP conf file>'
See how it is used in start script
if [ $CQ_USE_JAAS ]; then
Secure LDAP Password:
One more interesting Blog http://www.citytechinc.com/us/en/blog/2012/03/adobe_cq5_5_and_ldap.html
Hope fully all changes are covered. Shoot me any question if it is not clear for LDAP with CQ5.5.
Configure LDAP in CQ / AEM6
In CQ6 All login module can be configured as Pluggable Login Module. What that mean is there is no need to create JAAS config through start up param. You can configure your LDAP using OSGI config. Steps of how to do that can be found from
How to create OSGI config can be found from here http://www.wemblog.com/2012/10/how-to-work-with-configurations-in-cq.html
this is how sample LDAP config will look like in AEM6 (Here custom can be any thing)
Here is how content of these file look like,
There are more attribute as well please read above documentation for that.