PMDF System Manager's Guide

If the PMDF options LDAP_HOST, LDAP_PORT, and REVERSE_URL are specified in the PMDF option file (see Section 7.3.2), then each address passing through PMDF will be checked against the LDAP server specified by the LDAP_HOST and LDAP_PORT options, using the LDAP query specified by the REVERSE_URL option. If the LDAP query succeeds and returns a value, that value will be substituted in place of the original address.

For the REVERSE_URL option, standard LDAP URLs must be used, except with the host and port omitted, as the host and port are instead specified via the LDAP_HOST and LDAP_PORT PMDF options. That is, the LDAP URL should be specified as

ldap:///dn[?attributes[?scope?filter]]

where the square bracket characters [ and ] shown above indicate optional portions of the URL. The dn is required and is a distinguished name specifying the search base; it might correspond to the organization's top level in the Directory Information Tree, or it might correspond to a subset of the organization, based upon the domain name in the original address. The optional attributes, scope, and filter portions of the URL further refine what information to return. For address reversal, the desired attributes to specify returning would typically be the mail attribute (or some similar attribute). The scope may be any of base (the default), one, or sub. And the desired filter would typically be based upon the mailbox (local portion) of the incoming addresses. Certain substitution sequences may be used to construct the LDAP search URL; see Table 3-1 for details.