I know that this is very simple,
but when you configure your liferay first time with LDAP then this article will help you.
Follow below steps to configure LDAP with liferay :
1) Go to control panel of liferay and navigate portal setting as shown in below screen
2) Now click on Add button to add LDAP configuration (See below snapshot)
3) Once you provide proper Connection details of LDAP it will get connect with LDAP.
To check LDAP connection , you can click on Test LDAP Connection button.
4) Now you are done with LDAP connection and you have to configure it for import export function.
5) In liferay you can import users by user wise or group wise,
In User wise import , you can configure as per below snapshot
Here this data you can map with your LDAP as per the schema which you used in LDAP.
Now to test the users , you can click on button whether Import Search Filter is proper or not
OR
you can import by group wise which will have below configurations :
Here you just check that whether you mapped Import Search Filter proper or not
Also test LDAP group whether filter is proper or not.
5) So now we are done with Import functions and we will move forward for LDAP export function
For export from liferay to LDAP, you can configure as per below snapshot
6) Once all configuration done, save this LDAP profile to use
7) Also don't forget to mark below configurations
You are done with LDAP configuration with liferay 6.X Enjoy!!!