From owner-freebsd-net@FreeBSD.ORG Mon Aug 3 19:41:22 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 691FC106566C; Mon, 3 Aug 2009 19:41:22 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.delphij.net (delphij-pt.tunnel.tserv2.fmt.ipv6.he.net [IPv6:2001:470:1f03:2c9::2]) by mx1.freebsd.org (Postfix) with ESMTP id 0F4198FC1A; Mon, 3 Aug 2009 19:41:22 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from tarsier.geekcn.org (tarsier.geekcn.org [211.166.10.233]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by tarsier.delphij.net (Postfix) with ESMTPS id 2CE8D5C024; Tue, 4 Aug 2009 03:41:21 +0800 (CST) Received: from localhost (tarsier.geekcn.org [211.166.10.233]) by tarsier.geekcn.org (Postfix) with ESMTP id E8B9655CD9F9; Tue, 4 Aug 2009 03:41:20 +0800 (CST) X-Virus-Scanned: amavisd-new at geekcn.org Received: from tarsier.geekcn.org ([211.166.10.233]) by localhost (mail.geekcn.org [211.166.10.233]) (amavisd-new, port 10024) with ESMTP id reuLG05xl8Wj; Tue, 4 Aug 2009 03:40:22 +0800 (CST) Received: from charlie.delphij.net (adsl-76-237-33-62.dsl.pltn13.sbcglobal.net [76.237.33.62]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tarsier.geekcn.org (Postfix) with ESMTPSA id 6B0BA55CD9AC; Tue, 4 Aug 2009 03:40:16 +0800 (CST) DomainKey-Signature: a=rsa-sha1; s=default; d=delphij.net; c=nofws; q=dns; h=message-id:date:from:reply-to:organization:user-agent: mime-version:to:cc:subject:x-enigmail-version:openpgp:content-type:content-transfer-encoding; b=D7Fl6KNUiHei0Z8MmJeNn9YgR1T8XWx/9X5WeAhhlusNPZGlYSa5+kMbxm6yNqgqr aywZS0rNKno+GLwFVQ5vw== Message-ID: <4A773D09.3030404@delphij.net> Date: Mon, 03 Aug 2009 12:39:53 -0700 From: Xin LI Organization: The FreeBSD Project User-Agent: Thunderbird 2.0.0.22 (X11/20090803) MIME-Version: 1.0 To: Jack F Vogel X-Enigmail-Version: 0.95.7 OpenPGP: id=18EDEBA0; url=http://www.delphij.net/delphij.asc Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: em(4): sending ARP regardless of NOARP flag X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: d@delphij.net List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Aug 2009 19:41:22 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Jack, I have observed that, even if -arp is specified when adding an IP address to the em(4) interface, an ARP request is still being sent. Here is a tcpdump from my network environment: 11:15:01.370256 00:13:72:66:b5:d7 > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 60: Request who-has *.*.152.120 tell *.*.152.120, length 46 11:15:01.370270 00:15:17:92:39:0e > 00:13:72:66:b5:d7, ethertype ARP (0x0806), length 42: Reply *.*.152.120 is-at 00:00:5e:00:01:07, length 28 (The first ARP request was sent from a Dell branded Intel 82541EI based NIC, the latter is from a cheaper server that is part of CARP configuration which is unrelated to the problem in response to the ARP request) I was originally under the impression that there is some bug in our ARP code but with a bce(4) card, the problem does not exist. After a glance at e1000 driver code, it looks like that the e1000 NIC has a feature of hardware interception of ARP, can this be somehow connected? The hardware in question is 82541EI based: em1@pci0:7:8:0: class=0x020000 card=0x016d1028 chip=0x10768086 rev=0x05 hdr=0x00 vendor = 'Intel Corporation' device = '82541EI Gigabit Ethernet Controller' class = network subclass = ethernet Thanks in advance! Cheers, - -- Xin LI http://www.delphij.net/ FreeBSD - The Power to Serve! -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.12 (FreeBSD) iEYEARECAAYFAkp3PQkACgkQi+vbBBjt66A2CQCgt+8prSPRDKdOb61gdfj1zpcF q28An1/UXuo0bcEi4nwlUpYuqD8hR5Lo =56SA -----END PGP SIGNATURE-----