DCPM: bad dups

[Steve Marvell]

The main body of the problemw ill follow with the solution, but I
wonder about the following scenario:

Two entries are duplicates becase, other than port and db being the
same, the IP and canonical name are one in each one. Obviously, you
want to delete the IP one from the DB, so there is another stage
before being able to generate the list.

Can you see any other foibles?

Steve