From owner-freebsd-hardware Thu Jul 30 20:50:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id UAA23888 for freebsd-hardware-outgoing; Thu, 30 Jul 1998 20:50:08 -0700 (PDT) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from pyramid.interdomain.net.au (pyramid.interdomain.net.au [203.17.167.4]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id UAA23825 for ; Thu, 30 Jul 1998 20:50:02 -0700 (PDT) (envelope-from rha@interdomain.net.au) Received: (qmail 10496 invoked from network); 31 Jul 1998 03:49:55 -0000 Received: from obnoxious.interdomain.net.au (HELO ?203.17.167.127?) (203.17.167.127) by pyramid.interdomain.net.au with SMTP; 31 Jul 1998 03:49:55 -0000 Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 31 Jul 1998 13:51:24 +1000 To: freebsd-hardware@FreeBSD.ORG From: Richard Archer Subject: Support for passive backplane chassis? Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hello all! I am working on setting up Internet access to an office building with hundreds of ethernets. I want to isolate the individual ethernets as much as possible, and running a FreeBSD system to as a router/firewall seems to be a logical choice. The number of ethernet segments involved means building the routers out of normal four PCI slot motherboards would be unpleasant. Even with quad-port ethernet cards (like the ZNYX NetBlaster ZX346) each router would only be able to handle 15 segments. I'd finish up with 3 racks full of PCs to maintain! I am thinking of using a passive backplane system with 16 PCI slots. This would allow each router to handle up to 64 ethernet segments. But I can't find much information about how these interact with FreeBSD. I am concerned that either the multiple PCI buses would not be detected, or there would be lengthy delays introduced by transferring data across the bridge. Is the fact that the multiple-port ethernet cards each effectively contain a PCI-PCI bridge going to complicate matters? I've searched the mailing list archives, but any discussion on this topic dates back to 1996. Does anyone have experience with these devices they'd care to share? Also, the number of interrupts generated by 60 ethernet ports could get quite high. Each ethernet segment only has a few computers, but 60 networks averaging 100 packets per second each will still generate upwards of 6,000 int/sec. How many interrupts per second can FreeBSD handle in this situation? Would this be affected by delays passing data across the bridge? Yours sincerely, Richard Archer. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message