Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ukma!david
From: david@ms.uky.edu (David Herron -- One of the vertebrae)
Newsgroups: comp.mail.uucp
Subject: Re: pathalias ignores fast Internet connections
Keywords: if else do
Message-ID: <11938@s.ms.uky.edu>
Date: 19 Jun 89 13:28:19 GMT
References: <1207@altos86.UUCP> <3288@epimass.EPI.COM> <742@crdgw1.crd.ge.com> <3307@epimass.EPI.COM>
Reply-To: david@ms.uky.edu (David Herron -- One of the vertebrae)
Organization: U of Kentucky, Mathematical Sciences
Lines: 64

In article <3307@epimass.EPI.COM> jbuck@epimass.EPI.COM (Joe Buck) writes:
>In article <742@crdgw1.crd.ge.com> davidsen@crdos1.UUCP (bill davidsen) writes:
>> Let's not get carried away here, sending from a machine on the west
>>coast all the way to uunet and then back via internet to Berkeley is not
>>usually the best way to do things. There should be a better way to get
>>to ucbvax than uunet, starting in CA.

So make a UUCP link with one of the west coast machines who does gatewaying ...

But I'm really replying to Joe ...

...
>If my suggestion (about removing .foo.edu and host.foo.edu and so forth
>from the map for Internet sites) were taken, and it's cheaper for you
>to get to Berkeley than to uunet, your map data might have
>
>.edu   ucbvax!%s
>
>instead of
>
>.edu	uunet!%s

That extra information is there for a purpose.  It's so that specific
parts of domain name space can declare gateways for themselves which might
possibly be "more efficient".  It reduces load on the Official .edu
type gateways.  Etc, etc, etc.

>>  What we need is to change pathalias to reduct the cost of a transition
>>between nets, and thus generate better maps.
>
>As designed, pathalias doesn't know, when generating routes, that there
>is any relation between .com, .foo.com, and .bar.foo.com.  

I do see that a small change might be made to improve things.  Consider
a case where you have a .edu gateway and .podunk.edu gateway.  To reach
the .edu one "costs", say, 100 and the .podunk.edu one "costs" 10,000.
In that cast it's probably better to go by way of the .edu gateway.

I'm not proposing that someone teach pathalias about domains.  This could
be handled by a script of some sort, like

	run pathalias in the mode which generates costs as well as routes
						save the output in "paths1"
	look through paths1 doing
		if it doesn't have a ".", continue
		/* we know it's some domain name */
		look through the list of already known gateways and
			if we find one whose name is a "superset" of
			this one, then delete this route from paths1
			(superset means ".edu" is-superset-of ".podunk.edu")

But what do you do with .uucp hosts.  How does one decide if you want
to run such a script?  Or should everybody?

The danger I see is that, if everyone ran this script that some routing
loop might happen.  Oh, I see, the gateway site will have to delete themselves
from the list of sites doing gatewaying before they do *their* pathalias run.

(Erik, is the script I described up there the one you say you wrote last fall?)
-- 
<- David Herron; an MMDF guy                              <david@ms.uky.edu>
<- ska: David le casse\*'      {rutgers,uunet}!ukma!david, david@UKMA.BITNET
<-
<- New word for the day: Obnoxity -- an act of obnoxiousness