Ldap intergration

Hi,

We are looking to integrate client LDAP with portal.

Scenario is domain: xyz.com with ADS installed on windows 2008 server. Until this we are fine.

Ldap is installed on the domain on ports 50000, 50001.

Portal is running on a separate unix box.

When the user credentials are provided for LDAP authentication in portal we get error  Connection to LDAP server failed; check credentials.

We suspect that we might be missing some step LDAP configuration.  If any one has full documentation on windows 2008 R2 ldap + ads or can list down steps required will be helpful.

Regards,

Raj