From owner-freebsd-bugs@FreeBSD.ORG Tue Mar 9 04:00:32 2004 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3044316A4F4 for ; Tue, 9 Mar 2004 04:00:32 -0800 (PST) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0B6BF43D5D for ; Tue, 9 Mar 2004 04:00:32 -0800 (PST) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) i29C0Vbv008780 for ; Tue, 9 Mar 2004 04:00:31 -0800 (PST) (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.12.10/8.12.10/Submit) id i29C0Vbl008770; Tue, 9 Mar 2004 04:00:31 -0800 (PST) (envelope-from gnats) Resent-Date: Tue, 9 Mar 2004 04:00:31 -0800 (PST) Resent-Message-Id: <200403091200.i29C0Vbl008770@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, ian j hart Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EFEA616A4CE for ; Tue, 9 Mar 2004 03:59:05 -0800 (PST) Received: from www.freebsd.org (www.freebsd.org [216.136.204.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id E897343D2F for ; Tue, 9 Mar 2004 03:59:05 -0800 (PST) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.12.10/8.12.10) with ESMTP id i29Bx572091859 for ; Tue, 9 Mar 2004 03:59:05 -0800 (PST) (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.12.10/8.12.10/Submit) id i29Bx5Up091858; Tue, 9 Mar 2004 03:59:05 -0800 (PST) (envelope-from nobody) Message-Id: <200403091159.i29Bx5Up091858@www.freebsd.org> Date: Tue, 9 Mar 2004 03:59:05 -0800 (PST) From: ian j hart To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-2.3 Subject: kern/63982: em0 hardware checksum offloading causes bogus errors in tcpdump X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Mar 2004 12:00:32 -0000 >Number: 63982 >Category: kern >Synopsis: em0 hardware checksum offloading causes bogus errors in tcpdump >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Tue Mar 09 04:00:31 PST 2004 >Closed-Date: >Last-Modified: >Originator: ian j hart >Release: 4.9-RELEASEp3 >Organization: Cardinal Newman School >Environment: backup.cardinalnewman.lan 4.9-RELEASE-p3 FreeBSD 4.9-RELEASE-p3 #12: Tue Mar 9 10:13:10 GMT 2004 root@backup.cardinalnewman.lan:/usr/obj/usr/src/sys/GENERIC i386 patched with src/sys/dev/em from RELENG_4 >Description: Running tcpdump -v shows many packets marked as having bad checksums. The packets are delivered okay with correct checksums. This mainly affects UDP. I booted from disc2.iso for 4.7, 4.8, and 5.2.1RC and confirmed the problem there. One motherboard (GA-7VAXP-A Ultra) DOES work but all others tried so far, fail. Card in different slots, natch`. irq/timing? >How-To-Repeat: tcpdump -v | grep bad Then generate some UDP traffic >Fix: A workaround and proof of the source of the problem is to disable the hardware checksum. /usr/src/sys/dev/em/if_em.h #define EM_CHECKSUM_FEATURES (CSUM_TCP | CSUM_UDP) Set to zero >Release-Note: >Audit-Trail: >Unformatted: