ffj@ifistg.UUCP (07/08/88)
Can anyone tell me about their experiences with the RetixGate 2244 MAC Bridge. We are about to buy some of them and are interested in any comments on this bridge. Advanced thanks, Franz Fabian Computer Science Department, University of Stuttgart West Germany UUCP: ..!uunet!unido!ifistg!ffj ARPA: ffj%ifistg@uunet.uu.net CSNET: ffj%ifistg@germany.csnet
morgan@Jessica.stanford.edu (RL "Bob" Morgan) (07/09/88)
We have used one of the Retix bridges and found it to be as advertized: a no-frills bridge implementation with "medium" performance at an amazingly low price. The question of whether 6000 packets/sec forwarding is "good enough" (versus a DEC LANbridge's stated 12,000?) is a tricky one. We tested the bridge between a number of Sun clients and their server with no apparent ill effects. They are coming out with a bridge management package that runs on a PC and is ISO-based. Haven't seen it, but it looks like an interesting design, and it should greatly increase the value of the product. Any network box without management hooks is an invitation to headaches. - RL "Bob" Morgan Networking Systems Stanford
jerry@oliveb.olivetti.com (Jerry Aguirre) (07/13/88)
In article <3059@Portia.Stanford.EDU> morgan@Jessica.stanford.edu (RL "Bob" Morgan) writes: >They are coming out with a bridge management package that runs on a PC >and is ISO-based. Haven't seen it, but it looks like an interesting >design, and it should greatly increase the value of the product. Any >network box without management hooks is an invitation to headaches. I have trouble understanding this statement. Do you think that a repeater should have nework management hooks? Isn't a bridge just a slightly smarter repeater? (I am assuming an ethernet to ethernet bridge here. Not one using slower intermediate media.) 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? Granted without special filtering you have a large network that is vulnerable to many problems. But a bridge is not a router and even the best of management hooks is not going to fix that. The bridge can isolate traffic and provide some security from monitoring (but not spoofing). 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? 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.)
jqj@uoregon.uoregon.edu (JQ Johnson) (07/14/88)
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.