Date: Mon, 03 Jun 1996 08:29:40 -0700 From: bmah@cs.berkeley.edu (Bruce A. Mah) To: Garrett Wollman <wollman@lcs.mit.edu> Cc: "Christoph P. Kukulies" <kuku@gilberto.physik.rwth-aachen.de>, freebsd-questions@freefall.freebsd.org Subject: Re: route command w/o metrics (why?) Message-ID: <199606031529.IAA27560@premise.CS.Berkeley.EDU> In-Reply-To: Your message of "Mon, 03 Jun 1996 09:44:45 EDT." <9606031344.AA28071@halloran-eldar.lcs.mit.edu>
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Garrett Wollman writes: > <<On Mon, 03 Jun 1996 10:21:13 +0200, "Christoph P. Kukulies" <kuku@gilberto. > physik.rwth-aachen.de> said: > > > Just out of curiousity: Why does the BSD route command not require > > a metrics parameter? > > Why would it require one? What purpose would it serve? Well for starters, you could use a route with metric > 1 to set a backup route, in case a lower-metric route (configured using RIP or OSPF) went away. In most networks, this wouldn't be real useful because all of the routes would be advertised using a routing protocol anyways. However I've used it in situations where for administrative reasons I didn't have advertised routes through all of the links I was connected to. (If this was a bit vague on details, I'm trying to spare you the boring details of an experimental network setup we had here at Berkeley up until recently.) But for most situations (e.g. single-homed host, or multi-homed host running a routing protocol for all attached links) you're right, this doesn't serve a purpose. As a historical point, older BSD versions used to use the metric to distinguish between routes to directly-attached networks and routes through gateways. I always wondered why it couldn't figure this out from the list of interfaces in kernel. Cheers, Bruce.
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