From owner-freebsd-stable@FreeBSD.ORG Sat Mar 17 04:38:00 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F143B106564A for ; Sat, 17 Mar 2012 04:38:00 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159]) by mx1.freebsd.org (Postfix) with ESMTP id 6E17A8FC0C for ; Sat, 17 Mar 2012 04:38:00 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id q2H4bIYa065777; Sat, 17 Mar 2012 15:37:18 +1100 (EST) (envelope-from smithi@nimnet.asn.au) Date: Sat, 17 Mar 2012 15:37:18 +1100 (EST) From: Ian Smith To: Mike Tancsa In-Reply-To: <4F63A772.30406@sentex.net> Message-ID: <20120317135227.X80493@sola.nimnet.asn.au> References: <4F63A772.30406@sentex.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: FreeBSD-STABLE Mailing List Subject: Re: fxp entering promiscuous mode causing link to bounce X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Mar 2012 04:38:01 -0000 On Fri, 16 Mar 2012 16:49:54 -0400, Mike Tancsa wrote: > I dont recall seeing this on RELENG_7, but I dont have a box to test > with anymore confirm. On one box I upgraded to RELENG_8 I just > noticed the nic will bounce if I enable tcpdump on it. Sure enough, > trying on a different RELENG_8 box with an fxp nic shows the same > result. > > eg > > tcpdump -ni fxp0 -c 20 > > fxp0: link state changed to DOWN > fxp0: promiscuous mode enabled > fxp0: link state changed to UP > fxp0: link state changed to DOWN > fxp0: promiscuous mode disabled > fxp0: link state changed to UP > > I verified it on 2 different boxes. Is there a way to prevent this > from happening ? Confirmed on 8.2-RELEASE. I hadn't noticed as I tend to use tcpdump -p Mar 17 14:00:03 t23 kernel: fxp0: link state changed to DOWN Mar 17 14:00:03 t23 kernel: fxp0: promiscuous mode enabled Mar 17 14:00:05 t23 kernel: fxp0: link state changed to UP Mar 17 14:00:14 t23 kernel: fxp0: link state changed to DOWN Mar 17 14:00:14 t23 kernel: fxp0: promiscuous mode disabled Mar 17 14:00:16 t23 kernel: fxp0: link state changed to UP I've also noticed that it consistently takes a couple of seconds after enabling or disabling promisc mode before coming back UP here. There were several updates to fxp between 7 and 8.0 through 8.1-STABLE upto 8.2-R, concerning UP/DOWN occurrence and timing at boot, around suspend/resume and dhclient. I'd been watching it with some suspicion regarding a suspend/resume issue (that turned out to be usb-related). cheers, Ian