From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32234 invoked by alias); 27 Jan 2013 21:40:51 -0000 Received: (qmail 32224 invoked by uid 22791); 27 Jan 2013 21:40:50 -0000 X-SWARE-Spam-Status: No, hits=-3.1 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FAKE_REPLY_C,FREEMAIL_FROM,KHOP_RCVD_TRUST,KHOP_SPAMHAUS_DROP,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE X-Spam-Check-By: sourceware.org Received: from mail-ia0-f170.google.com (HELO mail-ia0-f170.google.com) (209.85.210.170) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 27 Jan 2013 21:40:18 +0000 Received: by mail-ia0-f170.google.com with SMTP id k20so3398077iak.29 for ; Sun, 27 Jan 2013 13:40:18 -0800 (PST) X-Received: by 10.50.217.167 with SMTP id oz7mr3586469igc.26.1359322818010; Sun, 27 Jan 2013 13:40:18 -0800 (PST) Received: from localhost (c-24-118-110-103.hsd1.mn.comcast.net. [24.118.110.103]) by mx.google.com with ESMTPS id hi2sm5018102igc.16.2013.01.27.13.40.16 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 27 Jan 2013 13:40:16 -0800 (PST) Date: Sun, 27 Jan 2013 21:40:00 -0000 From: Grant Edwards To: ecos-discuss@ecos.sourceware.org Message-ID: <20130127214014.GA13255@grante> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: [ECOS] Re: ARP-related problem X-SW-Source: 2013-01/txt/msg00027.txt.bz2 On 2013-01-25, Grant Edwards wrote: > I've been examining Ethernet traces from a customer site where there > appear to be problems associated with the eCos ARP table entry > timeouts. It seems this is a known problem with a known fix, so I thought I would follow-up just for the record... Bernd Edlinger has kindly pointed me to a patch he submitted that among other things fixes the periodic packet loss due to ARP entry timeouts: http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001656 It would be interesting to have a chat with whoever decided that letting the entry expire every 20 minutes [and thus potentially discarding tx packets] was the right thing to do. While it's obvious that discarding eCos's tx packets is part of the design of the BSD ARP subsystem, what I haven't figured out is why the TCP connection doesn't recover. The smart money is betting on Microsft as the culprit: one end of the TCP/IP connection is Windows 7, and the customer claims they never had the problem when using XP. How long as TCP/IP been around? It seems nothing is so old and well understood that it can't be screwed up by Microsoft... -- Grant -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss