From owner-freebsd-mobile@FreeBSD.ORG Mon Sep 5 13:17:12 2005 Return-Path: X-Original-To: freebsd-mobile@freebsd.org Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1C05116A41F for ; Mon, 5 Sep 2005 13:17:12 +0000 (GMT) (envelope-from gdt@ir.bbn.com) Received: from fnord.ir.bbn.com (fnord.ir.bbn.com [192.1.100.210]) by mx1.FreeBSD.org (Postfix) with ESMTP id CCE1A43D4C for ; Mon, 5 Sep 2005 13:17:11 +0000 (GMT) (envelope-from gdt@ir.bbn.com) Received: by fnord.ir.bbn.com (Postfix, from userid 10853) id 9B94953E6; Mon, 5 Sep 2005 09:17:10 -0400 (EDT) To: Folkert Saathoff References: <49D89F36-BEDB-4FAE-80BE-3F73FA74D773@feedface.com> From: Greg Troxel Date: 05 Sep 2005 09:17:10 -0400 In-Reply-To: <49D89F36-BEDB-4FAE-80BE-3F73FA74D773@feedface.com> Message-ID: Lines: 12 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: freebsd-mobile@freebsd.org, snap-users@kame.net Subject: Re: DUPlicate icmpv6 echo replies over wi0 X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Sep 2005 13:17:12 -0000 The 802.11 mac layer can cause duplicates. If the receiver hears the packet and sends an ack, but the ack is lost, the sender will retransmit, leading to two copies of the packet. In theory a receiver could filter dups, but I haven't noticed code to do this. So I would suggest trying with other traffic and seeing if it is really a ICMPv6-specific problem. Your description makes it sound to me like something other than 802.11 MAC-layer dups are happening, though. I would also suggest tcpdumping on the host behind the router and the hostap machine. -- Greg Troxel