What is ABAP 6 System? Do you mean ECC 6 system? If yes then you configure LDAP for UME. Check the below notes for more details
188371 Configuring the LDAP Connector
793191 FAQ: User master synchronization with LDAP directories
512230 Notes for using the LDAP transaction
My bad. Yes, we are on ECC 6.0.
We do not want to synchronize any data between LDAP and ABAP.
We already configured the LDAP connector.
All we want is when the user logs in to our ECC system using SAP GUI, they should be able to use their user id and password from LDAP.
Hi my friend
I think you meant to deploy GUI SSO for AD domain users without typing ID/password to access SAP as long as they already log on their PC with AD domain ID.
If your SAP instances run on windows hosts, then it's much easier to make it happen by just a few steps: find necessary crypto library in SWDC and load it, define parameters to activate SNC for AS ABAP, configure SNC tag in SU01 and logon pad. Here's the help link: http://help.sap.com/saphelp_nw70ehp1/helpdata/en/0d/482bb8013243f1b6e2439091e3022f/content.htm
But if your SAP runs on UNIX type host, you'll have to customize and generate AD kerberos library and load it by parameter snc/gssapi_lib, and it's OS dependent.
Please refer to thread SAP Using LDAP Authentication [really confusing] where this topic has been detailed discussed.