Patterns in Network Architecture: Naming and Addressing
- Did I ever tell you that Mrs. McCave
- Had twenty-three sons and she named them all Dave?
- Well, she did. And that wasn't a smart thing to do.
- You see, when she wants one and calls out, "Yoo-hoo!
- Come into the house, Dave!" she doesn't get one.
- All twenty-three Daves of hers come on the run!
- This makes things quite difficult at the McCaves'
- As you can imagine, with so many Daves.
- And often she wishes that, when they were born,
- She had named....
- [There follows a wonderful list of Dr. Seuss names she wishes she'd named
- them, and then concludes with this excellent advice.]
- But she didn't do it and now it is too late.
- —Dr. Seuss, Too Many Daves
Introduction
Many years ago when I started to work on the addressing problem, I remembered the opening lines to a Dr. Seuss story that I had read to my children far too many times. I thought it would make a good introductory quote for naming and addressing. So I dug into my kids' books to find it. Of course, I couldn't do that without reading the whole story through to the end for the great list of names she wished she had called them. But I had forgotten how it ended. I hit that last line and wondered whether Dr. Seuss had been sitting in all those addressing discussions and I just never noticed him! There was never more appropriate advice on naming and addressing than that last line.
The problem of addressing has confounded networking from the beginning. No other problem is so crucial to the success of a network; is so important to get right early and at the same time is so subtle, so philosophical, and so esoteric. No matter how you approach it. Once defined, it is difficult to change, and you may find yourself in the same situation as Mrs. McCave. If it is wrong and must be changed, the longer it takes to realize it, the more painful (and costly) it will be to change. If it is really wrong, the use of the network becomes cumbersome and arcane and eventually useless. Trying to fix it piecemeal as problems arise, only prolongs the agony, increases the cost, and increases the pain when the inevitable finally comes. But if it is right, many things become easier, and you scarcely realize it is there.