From owner-freebsd-net@FreeBSD.ORG Sun Feb 8 20:48:48 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0A25F448 for ; Sun, 8 Feb 2015 20:48:48 +0000 (UTC) Received: from lb3-smtp-cloud2.xs4all.net (lb3-smtp-cloud2.xs4all.net [194.109.24.29]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "Bizanga Labs SMTP Client Certificate", Issuer "Bizanga Labs CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 9CB41902 for ; Sun, 8 Feb 2015 20:48:46 +0000 (UTC) Received: from charlemagne.a43.boland.org ([62.194.208.247]) by smtp-cloud2.xs4all.net with ESMTP id pwoj1p0095LoPm601wok4i; Sun, 08 Feb 2015 21:48:44 +0100 Message-ID: <54D7CBAB.9060907@xs4all.nl> Date: Sun, 08 Feb 2015 21:48:43 +0100 From: Michiel Boland User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: freebsd-net@freebsd.org Subject: pcap sees its own frames Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Feb 2015 20:48:48 -0000 Hi. It appears the when I send a frame with pcap_inject, and then do a pcap_next, I get back the same frame I just sent. Is there a way to turn this off? There is a BIOCFEEDBACK ioctl on the underlying bpf fd but that does not appear to have any effect. The reason I don't want this behaviour is that GNS3 does not work when connecting to a host via bpf; the router sees its own packets, which breaks things like IPv6 DAD, bridging, etc. Cheers Michiel