From owner-freebsd-questions@FreeBSD.ORG Tue Jul 13 15:00:20 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EC85316A4CE for ; Tue, 13 Jul 2004 15:00:20 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8516A43D46 for ; Tue, 13 Jul 2004 15:00:20 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.12.10/8.12.10) id i6DF0JWj083701; Tue, 13 Jul 2004 10:00:19 -0500 (CDT) (envelope-from dan) Date: Tue, 13 Jul 2004 10:00:19 -0500 From: Dan Nelson To: Matin Tamizi Message-ID: <20040713150019.GC42183@dan.emsphone.com> References: <1089730314.92bcbe00matin@umd.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1089730314.92bcbe00matin@umd.edu> X-OS: FreeBSD 5.2-CURRENT X-message-flag: Outlook Error User-Agent: Mutt/1.5.6i cc: freebsd-questions@freebsd.org Subject: Re: How to drop a packet X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Jul 2004 15:00:21 -0000 In the last episode (Jul 13), Matin Tamizi said: > I'm using a FreeBSD box as a router in a test network. For the tests > that I am running, I need to be able to drop random packets and > observe the effects (responsiveness). > > What utilities in FreeBSD or C will allow me to perform the function > of dropping a random packet? You can use dummynet to create a pipe with arbitrary packet loss and delay, then run particular interfaces (or anything that can be matched via an ipfw rule) through that pipe. See the dummynet and ipfw manpages. -- Dan Nelson dnelson@allantgroup.com