I have tried moving out the /etc/ldap.conf as well as /etc/openldap/ldap.conf files. I have LDAP Authentication turned on in the TUI. It lets me define a host and base, but the entries are not saved to the above files. /etc/sysconfig/authconfig has a bunch of environmental variables, but none point to the ldap server. Yet it knows which LDAP server to fall back on when I try to log in over sshd. Of course I ask this because LDAP authentication is not working for me right now (well working on one machine, but not on another, although they have the same slapd.conf configuration). 
Which specific version of Redhat are you using? Why can't you use the GUI configuration tool?
I am on Fedora 13. My question is because I have the two machines configured exactly the same, both pointing to the same LDAP server. One authenticates fine, but the other fails. Therefore I think it is a difference in the client configuration and I want to look at it (no iptables or other variables in the picture). For now, I configured them similarly using the TUI, but I'd like to know where the pam_ldap.so module is picking its conf up from.