From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <4bone@gndrsh.dnsmgr.net> Received: from gndrsh.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 3551E3CB35; Tue, 2 Apr 2019 09:36:49 -0400 (EDT) Received: from gndrsh.dnsmgr.net (localhost [127.0.0.1]) by gndrsh.dnsmgr.net (8.13.3/8.13.3) with ESMTP id x32Damfe021481; Tue, 2 Apr 2019 06:36:48 -0700 (PDT) (envelope-from 4bone@gndrsh.dnsmgr.net) Received: (from 4bone@localhost) by gndrsh.dnsmgr.net (8.13.3/8.13.3/Submit) id x32DamSH021480; Tue, 2 Apr 2019 06:36:48 -0700 (PDT) (envelope-from 4bone) From: "Rodney W. Grimes" <4bone@gndrsh.dnsmgr.net> Message-Id: <201904021336.x32DamSH021480@gndrsh.dnsmgr.net> In-Reply-To: <20190401090258.144ff939@shemminger-XPS-13-9360> To: Stephen Hemminger Date: Tue, 2 Apr 2019 06:36:48 -0700 (PDT) CC: Michael Richardson , Cake List , ecn-sane@lists.bufferbloat.net X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII Subject: Re: [Ecn-sane] [Cake] The two SCE tests I have in mind X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 Apr 2019 13:36:50 -0000 > On Sun, 24 Mar 2019 13:32:03 +0100 > Michael Richardson wrote: > > > Jonathan Morton wrote: > > >> On 24 Mar, 2019, at 12:05 pm, Pete Heist wrote: > > >> > > >> tcpdump -r file.pcap udp port 2112 and greater 80 and "ip[1] != 0x1? > > >> > > >> ?greater 80? ignores the handshake packets and 0x1 is whatever TOS > > >> value we want to make sure the packets contain. We can use different > > >> filters for other traffic. > > > > > Bear in mind that the TOS byte contains ECN as well as DSCP fields, and > > > the latter is left-justified. > > > > libpcap should probably learn about DSCN bits to avoid people having to We need to teach tcpdump and wireshark what the new meaning of the 4th state ECT bits mean, and that NS now means ESCE. It already knows what CE and ECE are, iirc. > > think so much :-) > > > > Send patches to me/github. > > > > Libpcap is ancient history by now. It is like ifconfig, everyone still can't reprogram > their brain; but the tool is on life support. That is not correct, wireshark is a GUI built on top of libpcap, and quiet useless without a working libpcap. https://wiki.wireshark.org/libpcap However, the place(s) that need to learn about the bits so it can display them correctly is in the wireshark code, and also in the command line tcpdump code. > All development is happening on wireshark/tshark. Rarely, but not unheard of, changes do have to be made to libpcap, this however is not one of those cases. Libpcap is a very stable entity today. -- Rod Grimes rgrimes@freebsd.org