From owner-freebsd-current@FreeBSD.ORG Thu Aug 12 12:02:16 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DD60F16A4CE for ; Thu, 12 Aug 2004 12:02:16 +0000 (GMT) Received: from smarthost.enta.net (smarthost.enta.net [195.74.97.231]) by mx1.FreeBSD.org (Postfix) with ESMTP id AA03D43D1F for ; Thu, 12 Aug 2004 12:02:16 +0000 (GMT) (envelope-from jacs@gnome.co.uk) Received: from smartsmtp.enta.net (smtp.enta.net [195.74.97.230]) by smarthost.enta.net (Postfix) with ESMTP id 48557F67FE for ; Thu, 12 Aug 2004 12:51:32 +0100 (BST) Received: from smtp.enta.net (localhost [127.0.0.1]) by smartsmtp.enta.net (8.12.3/8.12.3) with ESMTP id i7CBr1b4010398 for ; Thu, 12 Aug 2004 12:53:02 +0100 (BST) (envelope-from jacs@gnome.co.uk) Received: from hawk.gnome.co.uk (81-31-113-153.adsl.entanet.co.uk [81.31.113.153]) by smtp.enta.net (Postfix) with SMTP id 3D4EE98B99 for ; Thu, 12 Aug 2004 12:53:01 +0100 (BST) Received: from [192.168.123.12] (hawk.gnome.co.uk [192.168.123.12]) by hawk.gnome.co.uk (8.12.10/8.12.10) with ESMTP id i7CBowkS013197 for ; Thu, 12 Aug 2004 12:50:59 +0100 (BST) (envelope-from jacs@gnome.co.uk) From: Chris Stenton To: FreeBSD Current Content-Type: text/plain Message-Id: <1092311458.13121.6.camel@hawk.gnome.co.uk> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 12 Aug 2004 12:50:58 +0100 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.44 Subject: bad tcp cksum on outgoing packets X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Aug 2004 12:02:17 -0000 I have just been doing some debugging on my 5.2.1 box and noticed that outgoing tcp packets on the box are coming up with bad checksums on tcpdump. I am using the nge interface. Here is a sample output. 12:44:29.458021 0:4:e2:10:60:83 0:c:6e:4e:a0:cc ip 82: hawk.gnome.co.uk.ssh > kite.gnome.co.uk.2167: P [bad tcp cksum 9420!] 2071:2099(28) ack 753 win 65535 (DF) [tos 0x10] (ttl 64, id 35623, len 68, bad cksum 0!) 12:44:29.642088 0:c:6e:4e:a0:cc 0:4:e2:10:60:83 ip 60: kite.gnome.co.uk.2167 > hawk.gnome.co.uk.ssh: . [tcp sum ok] 753:753(0) ack 2099 win 64956 (DF) (ttl 128, id 44852, len 40) Any ideas whats going on as the packet does not seem to be resent? Chris