Net::LDAP::Filter only checks for "well-formedness".

I guess you need to aks that to the people who created the RFCs
(i.e. the standards) for LDAP.

One possible explatation might be:
If you have the name of the object, you can make a more efficient query:

        $ldap->search(base => $YOUR_KNOWN_DN,
                                filter => '(objectclass=*)',
                                scope => base);

I.e. you set the search base to your known DN, set the scope to 'base',
(i.e. only the object given as base) and query for all objects.
This gives you the most efficient query if you already know a DN.

=> Using the DN alone on the left hand side of a filter is simply not
necessary.

Chris,
I am fully aware of DN as part of the left hand side in extensible matches.
But in those cases the filter searches for specific values of RDNs as parts of
the DN, not the full DN.

See above.

Best
Peter

--
Peter Marschall
pe...@adpm.de