Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!unmvax!ncar!ames!amdcad!sun!pitstop!sundc!seismo!uunet!munnari!vuwcomp!duncan From: duncan@comp.vuw.ac.nz (Duncan McEwan) Newsgroups: comp.mail.uucp Subject: Re: map wizardry - terminal links Message-ID: <14431@comp.vuw.ac.nz> Date: 8 Dec 88 02:05:52 GMT References: <513@ditka.UUCP> Reply-To: duncan@comp.vuw.ac.nz (Duncan McEwan) Organization: Comp Sci, Victoria Univ, Wellington, New Zealand Lines: 58 In article <513@ditka.UUCP> kls@ditka.UUCP (Karl Swartz) writes: [about terminal links, and keeping local sites out of the published maps to prevent other sites routing through them ...] >This would have been easy with domains ... This doesn't have much to do with Karl's idea, but is relevent to the subject of terminal links, and domains, etc. Some time ago I noticed the version of pathalias I have (version 9, which I think is the most recent that has been posted to c.s.u although it may not be the most recent available) was exhibiting strange behaviour when run over the published maps. As an example consider the following input data: ucbvax .berkeley.edu(DEDICATED) uunet(DEDICATED), somesite(DEMAND) somesite ucbvax(DEMAND) vuwcomp uunet(HOURLY) Running this through pathalias, you get the following output vuwcomp %s uunet uunet!%s somesite uunet!somesite!%s .berkeley.edu uunet!somesite!ucbvax!%s ucbvax uunet!ucbvax!%s Pathalias is not choosing the shortest route to the gateway to the .berkeley.edu domain due to uunet specifying its link to ucbvax as terminal. I understand that this is done to prevent paths being generated along Internet links unless the Internet site is the final destination, but it seems to me that that "anotherhost.berkeley.edu" is as much a part of the Internet as "ucbvax.berkeley.edu", and should therefore be accessible via the shorter path. After a bit of time looking at the code, I figured that an alias would help -- if you add the line ucbvax = .berkeley.edu to the input, the path to .berkeley.edu becomes "uunet!ucbvax!%s". Two questions: 1) Is there anything wrong with this solution, that I have missed? 2) If the answer to the above is "No", why do more sites not do it? There a number of entries for Internet sites in the current maps for which paths like the above are generated. If there is something wrong with such an alias is there anything else that can be done to cause saner paths to be generated. I seem to recall a posting a while back about strange paths to domains being generated by pathalias, but I don't remember if it was for the same reason, or whether a solution was posted. Apologies if this is all old-hat to everyone. Duncan