You are hereRHEL6 (beta)
This is just a case of RTFM but I thought I'd share...
We store our host information in ldap. Previously using ldap for host lookups was done by adding the appropriate entries to /etc/ldap.conf and changing nsswitch.conf.
With 6, nss_ldap has been replaced by nslcd, so I needed to change our setup a little.
I put the following into nslcd.conf
uid nslcd gid ldap uri ldap://ldap2.example.com