Path: utzoo!attcan!uunet!snorkelwacker!think!samsung!cs.utexas.edu!news-server.csri.toronto.edu!white.toronto.edu!cks From: cks@white.toronto.edu (Chris Siebenmann) Newsgroups: comp.mail.uucp Subject: Re: A Small-Memory Pathalias? Message-ID: <1990Mar22.134838.24458@jarvis.csri.toronto.edu> Date: 22 Mar 90 18:48:38 GMT References: <1990Mar19.030224.16305@usenet.ins.cwru.edu> <1990Mar20.161623.3712@druid.uucp> Organization: Ziebmef home away from home Lines: 29 karl@ficc.uu.net (Karl Lehenbauer) writes: | Alternatively, you can run pathalias on an extract of the database, say for | your city or state, then use the smart-host definition to forward any mail | that pathalias can't resolve with your path database to a nearby site that | processes all the maps. The problem with this approach is that you can end up with seriously non-optimal links listed, when they should really go through your smarthost. This happens when people inside your region have "backup" low-quality links to sites outside it; the explicitly mentioned low quality route then makes it into the paths file, and is used for your mail. One solution is to filter out all routes with a cost above a certain limit; with the right limit, you can drop almost all the bad links without loosing too many good links. Another useful trick is to strip the paths file of everything that has your smart host as the first hop (since it will go there anyways). An "ideal" regional map can be made by generating a full map and throwing out all paths to sites outside the region (domains may make this slightly problematic). Unfortunately, you need the full maps and enough memory to process them to do this, so it's something only large sites generating maps for other people would do. -- "This will be dynamically handled, possibly correctly, in 4.1." - Dan Davison on streams configuration in SunOS 4.0 cks@white.toronto.edu ...!{utgpu,utzoo,watmath}!utcsri!white!cks