From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Punjabi Subject: RE: 802.1AD packets - Kernel changes ether type from 88A8 to 8100 on all packets. Date: Tue, 15 Apr 2014 01:34:47 +0000 Message-ID: References: ,<1397319636.1789.11.camel@localhost.localdomain>,<5349729C.3020602@redhat.com>,<87sipgsen9.wl%atzm@stratosphere.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: Toshiaki Makita , "netdev@vger.kernel.org" To: Atzm Watanabe , Daniel Borkmann Return-path: Received: from blu0-omc4-s14.blu0.hotmail.com ([65.55.111.153]:2941 "EHLO blu0-omc4-s14.blu0.hotmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828AbaDOBjx convert rfc822-to-8bit (ORCPT ); Mon, 14 Apr 2014 21:39:53 -0400 In-Reply-To: <87sipgsen9.wl%atzm@stratosphere.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: >>> Hi. >>> >>> Though I'm not an expert with libpcap, I feel tcpdump sometimes shows a >>> wrong vlan protocol (if vlan_tci is used). >>> >>> Maybe this topic has relevance? >>> >>> packet: deliver VLAN TPID to userspace >>> http://marc.info/?l=linux-netdev&m=138728859001934&w=2 >>> http://marc.info/?l=linux-netdev&m=138728859601935&w=2 >>> http://marc.info/?l=linux-netdev&m=138728860101937&w=2 >>> http://marc.info/?l=linux-netdev&m=138728860601939&w=2 >> >> The issue seems not to be in AF_PACKET as it just 'playes dumb' and propagates >> what has been set in the skb as metadata to user space e.g., see ... > > Yes. > Also I sent a small pull-request for libpcap via github to fix this > issue about 2 weeks ago, but it is not pulled yet, still opened: > > https://github.com/the-tcpdump-group/libpcap/pull/346 Thanks Atzm and everyone for clarifying that and pointing me in the right direction. Was not too sure where to begin looking. I will apply the individual patches and try the 802.1AD filtering on the bridge. Appreciate your help. Best Regards, Dennis