From owner-freebsd-net@freebsd.org Tue Feb 6 22:47:41 2018 Return-Path: <owner-freebsd-net@freebsd.org> Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4A129F0ED6C for <freebsd-net@mailman.ysv.freebsd.org>; Tue, 6 Feb 2018 22:47:41 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [78.47.246.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id B6198870A0 for <freebsd-net@freebsd.org>; Tue, 6 Feb 2018 22:47:40 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221] (may be forged)) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id w16MlXVZ064143 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 6 Feb 2018 23:47:34 +0100 (CET) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: davida@truespeed.com Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id w16MlPGX063666 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Wed, 7 Feb 2018 05:47:26 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: tcpdump filter not functioning correctly with igb on FreeBSD 11.1 To: David Athay <davida@truespeed.com> References: <95AA0EAB-B3D6-4E68-83B2-914894D6FB90@truespeed.com> <5A7A1657.4050706@grosbein.net> <E149211C-9207-4162-950D-1BA788AA3A5F@truespeed.com> <5A7A19DD.6050400@grosbein.net> <64C4AA32-5A49-4D6F-B7A7-93CDB0E59F09@truespeed.com> <5A7A24DC.0@grosbein.net> <293C7809-A1AE-4040-8963-F9A6802CB898@truespeed.com> <5A7A29D6.3050307@grosbein.net> <DBA7BD66-CDB7-4FF2-88E4-EBC2B71E1F3E@truespeed.com> Cc: freebsd-net@freebsd.org From: Eugene Grosbein <eugen@grosbein.net> Message-ID: <5A7A3079.4080404@grosbein.net> Date: Wed, 7 Feb 2018 05:47:21 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <DBA7BD66-CDB7-4FF2-88E4-EBC2B71E1F3E@truespeed.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=2.2 required=5.0 tests=BAYES_00, LOCAL_FROM, RDNS_NONE autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains * 1.9 RDNS_NONE Delivered to internal network by a host with no rDNS X-Spam-Level: ** X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Networking and TCP/IP with FreeBSD <freebsd-net.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-net/> List-Post: <mailto:freebsd-net@freebsd.org> List-Help: <mailto:freebsd-net-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-net>, <mailto:freebsd-net-request@freebsd.org?subject=subscribe> X-List-Received-Date: Tue, 06 Feb 2018 22:47:41 -0000 07.02.2018 5:26, David Athay wrote: >> 802.1Q vlan header can be a reason for exactly such behaviour. >> Please add -e flag to tcpdump flags and post output again. > > # /usr/local/sbin/tcpdump -eni igb0 not port 22 |less > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on igb0, link-type EN10MB (Ethernet), capture size 262144 bytes > 22:19:25.589577 ac:1f:6b:13:a2:nn > 10:cd:ae:de:e9:nn, ethertype 802.1Q (0x8100), length 258: vlan 10, p 0, ethertype IPv4, X.X.X.X.22 > 77.100.156.Y.52743: Flags [P.], seq 418521610:418521798, ack 196067467, win 1026, options [nop,nop,TS val 602985028 ecr 731470580], length 188 Well, that explains everything. You should use "vlan and not port 22" and "vlan and host X.X.X.X" (same without "not") when filtering vlan-tagged traffic as documented in the pcap-filter(7) manual page or else you get wrong results. "Works as intended". Deinstall extra tcpdump/libcap packages, if you do not need them.