taylor@hplabsc.UUCP (02/27/87)
in news.sysadmin, David Lesher at ncoast.UUCP comments: > I regularly see posting [like] "I would have mailed but my mailer choked.." > Now the same thing often happens to me...it is very wasteful of net.money > would it not be worthwhile to devote some fraction of net.genuis/net.GOD > (s) resources to inventing better, more dependable, mailers? I will state something that might be viewed (inevitably) as controversial: the mail systems we have are fine. There is nothing wrong with them (hang on before you slam down that "F" key!) but rather what we're seeing is the problems of: 1. having a system that expects dynamic routing in a static routing universe (e.g. pathalias) 2. having this system phased out (e.g. the use of 'domains') 3. not having the new system implemented yet much of anywhere 4. some serious delusions about how reliable the software is going to be. What this means, I surmise, is that the main reason we're seeing people unable to reply to postings and/or get email addresses is that we've reached a point where people don't really want to mess with the pathalias style of addressing (the static routing system) and where we can't rely on 'core mail backbone' sites (like the ex-ihnp4) to reroute stuff based on real paths (the fake-dynamic routing that smail allows). At the same time, since there is a perceived need for domains as a way to break up our massive ".UUCP" domain into smaller, more manageable chunks, we're seeing hostnames that are from out of the twilight zone as far as any pathalias system is concerned ANYway. "hplabs.HP.COM" is a fine example of this... For reasons I shan't enter here, ignoring domain information on an electronic address (e.g. "hplabs.HP.COM" --> "hplabs") is a very bad idea... What we're supposed to end up with is a system that says "oohhh... you're sending mail to <hostname>.HP.COM (or <hostname>.<localdomain>.HP.COM) so I'll just send it to machine X". As we further and further subdivide the UUCP domain into pieces (.EDU, .STANFORD.EDU, CS.STANFORD.EDU, etc) we should theoretically see simpler and simpler delivery systems. In reality, however, I suspect that it'll be quite a bit further along before we 'shake out' the system and get some real reliability. There are some inherent problems with static routing information masquerading as dynamic routing information that are poised to attack... BUT as far as what we're talking about here, the best solution I can make is for people to have mail systems that grab not only the From: address in the posting, but the Path: address too, and read the Path: backwards until it finds a 'backbone' that it knows (you can have a file containing the 10 or 15 main ones, if you want) and then figures out the optimal (static, alas) route to that backbone. For example, your posting has the headers: Path: hplabsc!hplabs!hp-sdd!ncr-sd!ncrcae!ece-csc!mcnc!seismo!lll-lcc!ptsfa!ihnp 4!cbatt!cwruecmp!hal!ncoast!wb8foz From: wb8foz@ncoast.UUCP (David Lesher) First we should check the From: address and (as would really happen) figure out that we have no idea how to get email to ncoast.UUCP. So as an alternative plan, instead of dropping it there, we'd read the Path: line and start from the right, building up a longer and longer route until we find a host that we know we can get to: hal!ncoast!wb8foz cwruecmp!hal!ncoast!wb8foz cbatt!cwruecmp!hal!ncoast!wb8foz We know how to get to 'cbatt' (from hplabs it's simply via 'cbosgd') so we now have the address: cbosgd!cbatt!cwruecmp!hal!ncoast!wb8foz which is pretty reasonable. The advantage to this scheme is that it is indeed dynamic - it only finds routes that are actually those that have been taken in the past few days (assume current articles). The list of backbone sites could be as small as 20 or 30 and we'd be ok...(check the list in the Path: line above - there are 5 'backbones' in the route: hplabs, mcnc, seismo, ihnp4, and cbatt). Gee... neat idea. Maybe I should implement it or something. Anyone have any comments? -- Dave Taylor --