The incorrect domain name was specified on the command line.
The nisDomain attribute is not set in the DIT to represent the entry point for the specified client domain.
Access control information is not set up properly on the server, thus disallowing anonymous search in the LDAP database.
An incorrect server address passed to the ldapclient command. Use ldapsearch to verify the server address.
An incorrect profile name passed to the ldapclient command. Use ldapsearch to verify the profile name in the DIT.
Use snoop on the client's network interface to see what sort of traffic is going out, and determine to which server it is talking.