From owner-freebsd-questions@FreeBSD.ORG Thu Apr 3 19:00:43 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8BD3837B401 for ; Thu, 3 Apr 2003 19:00:43 -0800 (PST) Received: from yowie.cc.uq.edu.au (yowie.cc.uq.edu.au [130.102.2.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 69AC143FDD for ; Thu, 3 Apr 2003 19:00:40 -0800 (PST) (envelope-from csmith@its.uq.edu.au) Received: from its.uq.edu.au (tobermory.its.uq.edu.au [130.102.152.68]) by yowie.cc.uq.edu.au (8.12.9/8.12.9) with ESMTP id h3430dfI012223 for ; Fri, 4 Apr 2003 13:00:39 +1000 (GMT+1000) Date: Fri, 4 Apr 2003 13:00:38 +1000 Content-Type: text/plain; delsp=yes; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v551) From: Christopher Smith To: freebsd-questions@freebsd.org Content-Transfer-Encoding: 7bit In-Reply-To: Message-Id: <9D331AD4-6649-11D7-BABB-000502F96668@its.uq.edu.au> X-Mailer: Apple Mail (2.551) Subject: Re: Weird traceroute problem - SOLVED X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 04 Apr 2003 03:00:43 -0000 It appears I've been bitten by a bug in the vlan code. I noticed while tcpdumping that the icmp time-exceeded packets were getting back to the vlan parent interface, but not to the vlan interface itself. This thread appears to describe the underlying problem: http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF- 8&threadm=3E05A429.7080506_obluda.cz%40ns.sol.net&rnum=5&prev=/ groups%3Fq%3Dfreebsd%2Bhardware%2Bvlan%2Bbug%26hl%3Den%26lr%3D%26ie%3DUT F-8%26oe%3DUTF- 8%26selm%3D3E05A429.7080506_obluda.cz%2540ns.sol.net%26rnum%3D5 And this PR referenced in it has a patch that fixes the problem: http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/46405 I'm guessing this will only affect some people, as the problem was intermittent (depending on the intervening routers). The ones that were sending back the ICMP packets that were triggering the bug were "Cisco Catalyst 6500s running native IOS" (the networking people here tell me). Presumably these routers change the priority of some ICMP packets ? In any event, can someone please merge the patch in the PR referenced above into the main source tree, because the problem it triggers is rather mystifying :). -- +- Christopher Smith, Systems Administrator ------------------------------+ | Server & Security Group, Information Technology Services | | The University of Queensland, Brisbane, Australia, 4072 | +- Ph +61 7 3365 4046 | email csmith@its.uq.edu.au | Fax +61 7 3365 4065 -+