From owner-freebsd-isp Tue Jul 22 22:38:51 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id WAA25521 for isp-outgoing; Tue, 22 Jul 1997 22:38:51 -0700 (PDT) Received: from mail.webspan.net (root@mail.webspan.net [206.154.70.7]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id WAA25514 for ; Tue, 22 Jul 1997 22:38:48 -0700 (PDT) Received: from orion.webspan.net (orion.webspan.net [206.154.70.5]) by mail.webspan.net (WEBSPAN/970608) with ESMTP id BAA24137; Wed, 23 Jul 1997 01:38:47 -0400 (EDT) Received: from orion.webspan.net (localhost [127.0.0.1]) by orion.webspan.net (WEBSPAN/970608) with ESMTP id BAA08430; Wed, 23 Jul 1997 01:38:46 -0400 (EDT) To: zoonie cc: Michael Slater , freebsd-isp@FreeBSD.ORG From: "Gary Palmer" Subject: Re: Monitoring the IP usage of a single IP address on an ethernet In-reply-to: Your message of "Wed, 23 Jul 1997 00:44:25 EDT." Date: Wed, 23 Jul 1997 01:38:46 -0400 Message-ID: <8428.869636326@orion.webspan.net> Sender: owner-freebsd-isp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk zoonie wrote in message ID : > snmp hub should do). if you have a cisco router you can turn on IP > accounting. Just a warning: Cisco's IOS does allow you to turn on IP accounting, and it does generate useful information, however, it comes at a price. By default, Ciscos do something called `fast switching' which means that the packet is delivered to the queue for the destination interface as part of servicing the interrupt. Withouth fast switching, the packet is just put in an input queue and processed as and when the router gets round to it (thats a gross oversimplification). If you are running routing processes (e.g. OSPF, EIGRP, BGP) on that box too, it can lead to degraded service. Fast switching is still disabled, even if you turn off IP accounting, until the next reboot. (Apparently at least one major US national dialup provider found this the hard way *grin*) If you have a smart hub or a switch with a SNMP agent, and you just want basic bytes in/out, thats probably the best way to go. If you want more detailed statistics (e.g. bytes for ftp, bytes for telnet, etc) you'll need an IPFW/IPFilter based solution, Gary -- Gary Palmer FreeBSD Core Team Member FreeBSD: Turning PC's into workstations. See http://www.FreeBSD.ORG/ for info