From owner-freebsd-net Wed May 13 14:20:52 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA18573 for freebsd-net-outgoing; Wed, 13 May 1998 14:20:52 -0700 (PDT) (envelope-from owner-freebsd-net@FreeBSD.ORG) Received: from cortex.NSMA.Arizona.EDU (cortex.NSMA.Arizona.EDU [128.196.180.125]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id OAA18542 for ; Wed, 13 May 1998 14:20:44 -0700 (PDT) (envelope-from ddw@cortex.NSMA.Arizona.EDU) Received: from cortex (localhost [127.0.0.1]) by cortex.NSMA.Arizona.EDU (8.7.5/8.7.5) with ESMTP id OAA27971; Wed, 13 May 1998 14:24:58 -0700 (MST) Message-Id: <199805132124.OAA27971@cortex.NSMA.Arizona.EDU> To: freebsd-net@FreeBSD.ORG Cc: ddw@cortex.NSMA.Arizona.EDU Subject: Number of hubs on a net... In-reply-to: Your message of "Wed, 13 May 1998 23:31:03 +0300." Date: Wed, 13 May 1998 14:24:58 -0700 From: Doug Wellington Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Previously: >at my office I want to expand my network with installing >new hubs, how many hubs I can connect together? Hubs are just multiport repeaters, and we follow the "four repeater rule" - that is, no more than four repeaters between any two devices. Of course, once you get to a bridge, switch (which is just a multiport bridge) or router, you can start counting all over again... >and what can happen if I install too many hubs like this? >would it cause collusion on my network? No, it won't cause a collision, and that is the very problem. Computers at the ends of the network won't realize that the last packet they sent really did result in a collision, and they won't know to resend it. >(well another thing I should ask it, why does collusion >occurs on a network?) Ethernet is designed that way. It's like being at a party. Anyone can talk at any time, and sometimes more than one person will start to talk at the same time. Then each person, or each network device, will wait a small period of time and then start to listen again to see if anyone else is talking. If nobody else is talking, then that one can try again. The other way to set up a network is with each computer passing a "token" around. Only the computer with the token can talk. If that computer doesn't need to talk, it just passes the token on. (Token ring or token bus...) Doug Wellington ddw@nsma.arizona.edu Network and System Administrator ARL, Division of Neural Systems, Memory and Aging The University of Arizona, Tucson, AZ (520) 626-6023 (520) 291-0481 pager (520) 626-2618 fax I DON'T buy anything from spammers, and I KEEP TRACK OF WHO SPAMS ME. I put up with ads on the TV because they pay for programming. When spammers pay for the Internet, then I'll start putting up with spam. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message