Many years ago (in the last century) I wrote some M2M applications for a company Intranet that used oddball ports. Not initially for security reasons, but to keep various functions logically separated. The added benefit was that our Intranet was pretty well firewalled from the Evil Outside World. All the ports used were blocked, keeping script kiddies (but not internally infected machines) from probing our stuff.
Biting the hand that feeds IT
