Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!hplabs!hp-pcd!uoregon!jqj From: jqj@uoregon.uoregon.edu (JQ Johnson) Newsgroups: comp.dcom.lans Subject: Re: RetixGate 2244 MAC Bridge - (nf) Message-ID: <2396@uoregon.uoregon.edu> Date: 14 Jul 88 14:42:35 GMT References: <281@ifistg.UUCP> <3059@Portia.Stanford.EDU> <25335@oliveb.olivetti.com> Reply-To: jqj@drizzle.UUCP (JQ Johnson) Organization: University of Oregon, Computer Science, Eugene OR Lines: 33 In article <25335@oliveb.olivetti.com> jerry@oliveb.UUCP (Jerry Aguirre) writes: > Do you think that a >repeater should have nework management hooks? Isn't a bridge just a >slightly smarter repeater? Yes, and the availability of network management hooks is one reason to prefer a bridge over a repeater. Note that a router is just a slightly smarter bridge :-). > >Assuming the bridge is doing only ethernet address filtering and doesn't >do multicast or other user specified filtering, do you need to manage it >any more than you would manage a repeater? Yes. > >So, if one views a bridge as an inteligent repeater then what management >tools are needed? The only one I can think of is statistics and that >could probably be better generated from other sources. I mean, do you >really trust the bridge to tell you about its own performance? Yes, I think that traffic data is important. A bridge is VERY useful for analyzing (first pass) which parts of your network are getting overloaded. So is topology; if your bridges support automatic pruning to build a spanning tree, you want to be able to find out what tree is currently configured. So is the ability to filter multicast and broadcast. So is the ability to remotely segment your network for debugging serious problems. >Given the high cost of repeaters, why would someone want to use one >instead of one of the Retix bridges? (An honest question, I would like >to see the tradeoffs discused.) Retix throughput is only about half of full Ethernet bandwidth, so in some applications you need a repeater for speed unless you want to pay a lot more for your bridge. Retix price is about twice that of a dumb repeater, so in some applications you want a repeater for price. On the other hand, on our campus I have a dozen 2244Ms and no repeaters -- I'm using the Retix in place of a repeater.