From owner-freebsd-net@FreeBSD.ORG Wed Sep 17 23:14:53 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 59A3916A4B3 for ; Wed, 17 Sep 2003 23:14:53 -0700 (PDT) Received: from silver.he.iki.fi (helenius.fi [193.64.42.241]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0251143FDD for ; Wed, 17 Sep 2003 23:14:52 -0700 (PDT) (envelope-from pete@he.iki.fi) Received: from he.iki.fi (h81.vuokselantie10.fi [193.64.42.129]) by silver.he.iki.fi (8.12.9/8.11.4) with ESMTP id h8I6EmSq064712; Thu, 18 Sep 2003 09:14:48 +0300 (EEST) (envelope-from pete@he.iki.fi) Message-ID: <3F694D56.9040609@he.iki.fi> Date: Thu, 18 Sep 2003 09:14:46 +0300 From: Petri Helenius User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Edwin Groothuis References: <20030917182850.Q52432-100000@mail.econolodgetulsa.com> <20030918014203.GA59403@k7.mavetju> In-Reply-To: <20030918014203.GA59403@k7.mavetju> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-net@freebsd.org cc: Josh Brooks Subject: Re: I would like to tcpdump and get all the packets... X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Sep 2003 06:14:53 -0000 Edwin Groothuis wrote: >On Wed, Sep 17, 2003 at 06:31:03PM -0700, Josh Brooks wrote: > > >>Whenever I run: >> >>tcpdump -vvv >> >>when I am finished, I am surprised to see: >> >>27441 packets received by filter >>7866 packets dropped by kernel >> >> > >That's because the buffer of captures-but-not-yet-processed packets >in tcpdump was filled up. In other words, your system is to slow >to process the amount of traffic going through your machine. > > > Sure, but because the bug in pcap-bpf.c there is no way to set the buffer above 32768 without recompiling the library after applying the patch. This bug should be fixed in the FreeBSD copy of libpcap because tcpdump folks seem to be quite dormant. Pete