From owner-freebsd-current Fri Apr 24 02:52:47 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id CAA07137 for freebsd-current-outgoing; Fri, 24 Apr 1998 02:52:47 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id CAA07073 for ; Fri, 24 Apr 1998 02:52:24 -0700 (PDT) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id KAA20818; Fri, 24 Apr 1998 10:14:37 +0200 From: Luigi Rizzo Message-Id: <199804240814.KAA20818@labinfo.iet.unipi.it> Subject: Re: Bridging... To: gurney_j@resnet.uoregon.edu Date: Fri, 24 Apr 1998 10:14:37 +0200 (MET DST) Cc: current@FreeBSD.ORG In-Reply-To: <19980424005740.35254@hydrogen.nike.efn.org> from "John-Mark Gurney" at Apr 24, 98 00:57:21 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Luigi Rizzo scribbled this message on Apr 24: > > I am trying to see what could be the best way to implement bridging > > within FreeBSD. The main app would be to connect 10/100 Mbit ... > think, FreeBeSwitcheD on a floppy... :) actually, i have been using pc-based bridges (with code derived from netboot) for a long time -- look at my web page and search for PCbridge 3 . The code compiles on FreeBSD and can be run off a floppy or an EPROM. >From the point of view of efficiency this is better since with certain hardware it does not need to transfer the whole packet to main memory, but only the interesting parts -- headers etc. . Since the bus bandwidth is often the bottleneck for ISA cards, this is very efficient. The negative side is that the netboot only support a limited set of adapters, and no 100Mbit unit. So it would take a lot of work to port the driver to make it work with netboot, and it would need a lot of mainteinance with newer hardware. > it shouldn't be to hard to keep track of what interface has what hardware > address... and it wouldn't have to be limited to ip either... and think, > an 8meg machine could support up to 400k machines... which is a bit > better than most switches support... the filter needs not to be precise. PCbridge uses a small (64K) hash table with room for 8k different addresses. When you have a conflict you simply forward on all interfaces. In the five years i have been using this code i have never had a problem with leaks. cheers luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message