Path: utzoo!attcan!uunet!husc6!bloom-beacon!mcgill-vision!mouse From: mouse@mcgill-vision.UUCP (der Mouse) Newsgroups: comp.mail.uucp Subject: Re: Rerouting considered GOOD Message-ID: <1319@mcgill-vision.UUCP> Date: 1 Oct 88 10:27:13 GMT References: <8809212215.AA21035@naggum.se> Organization: McGill University, Montreal Lines: 94 In article <8809212215.AA21035@naggum.se>, erik@naggum.se (Erik Naggum) writes: > I have based my arguments [against aggressive rerouting] on the > following terse premises: > [four premises] > I also have abstracted your (collective) arguments as follows > 1. A mail sender can be demanded to know the network topology of the > world when he wants to send mail to someone I don't think even Paul Vixie has claimed this. But the sender may know something specific about the topology and want to express it. > 2. Registration is just a way to make it harder for people to get on > the net I don't recall anyone saying registration is *just* that. > 4. It's impractical or impossible to know the network topology of the > world at the backbone sites It's impractical or impossible for anyone to know the network topology of the world, period. In the time it's taken me to compose this letter, the network topology has most likely changed somehow. How do you propose to distribute this change to all the aggressive rerouters before my letter I sent an hour ago works its way over there and gets rerouted through a now-nonexistent link? > At my site, I do the following things with incoming mail: > 1. If it has a bangpath in the headers, I convert it to > @.uucp, and store the bangpath away for future use. Hang on a moment while I mark naggum DEAD....there. > To sum up, and make statements you can quote (instead of all the text > above), when you want to attack my views: > 1. A node which is not registered does not exist. > 2. Non-existent (unregistered) nodes can't send mail. This is a dreadfully narrow-minded view of the world. How about this: you disconnect from the rest of the net, then you won't be bothered by all us unregistered machines who happen to want to talk to one another. > 3. A bang path is the means, the delivery the end. Usually, though explicit paths have their place: for testing, or to avoid a machine for whatever reason.... > 4. The maps should be updated as soon as a change occurs. They should be, but can't possibly be. And they certainly can't be distributed immediately. > 5. We should get away from bangpaths, and switch to domains. I think I disagree. From what I've heard, this switch would turn the net from a graph with links all over the place into a tree (or something close to it). This is very vulnerable to failure, particularly of a machine near the center of the tree. (I wonder what would happen if, say, uunet got hit by lightning....) The point-to-point nature of uucp makes a flat namespace very desireable; unfortunately, there are simply too many machines for that! > 6. Address parsing is not difficult. True, most of the time. So? > 7. Rewriting is OK, since it only transforms something which works, > but is outside the standard to something which is inside the standard > (and still works). If your reason were true, your conclusion would be. Unfortunately, aggressive rewriting often transforms something which would work into something which doesn't work. For example, suppose someone sends a letter to mcgill-vision!spock!joesmith. If this were treated sensibly, it would be routed as necessary to reach mcgill-vision, who would then look at spock!joesmith and send it over the Ethernet here to our machine spock. This is a perfectly valid bangpath and always has been. However, if it hits an aggressive rerouter it'll end up at a high school in Connecticut instead. Or get dropped on the floor somewhere. Or will you try to tell me that spock - our spock - doesn't exist? I'm sure the people who use it every day will be interested to hear that. > Thank you for reading my long note. I hope I have managed to express > myself, not necessarily to your liking, but unambigously and clear. For the most part, you have been. der Mouse old: mcgill-vision!mouse new: mouse@larry.mcrcim.mcgill.edu