To export the LDIF from the command line, on the PDC :-

root@PDC-> slapcat –l  /tmp/my.ldif


Which creates a “Slap Compatible”  LDIF.   
Normal LDIFs require the data in a certain order, SLAP is a bit more intelligent 
so the LDIF does not work necessarily with other tools.

Then scp my.ldif to /tmp on the BDC.
 

Clear Out:

After install (as long as the machines are to be identical) stop SLAPD and
remove the contents of the databases. 
Quickest way is (on BDC):-

root@BDC-> service slapd stop 

root@BDC-> rm –f /usr/local/var/openldap-data/*

To import the data:

root@BDC-> slapadd –l  /tmp/my.ldif

root@BDC-> chown  ldap:ldap  /usr/local/var/openldap-data/*

And restart SLAPD

As usual, ymmv.