From owner-freebsd-net@FreeBSD.ORG Wed Aug 1 22:12:40 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 821) id 6F3F7106566B; Wed, 1 Aug 2012 22:12:40 +0000 (UTC) Date: Wed, 1 Aug 2012 22:12:40 +0000 From: John To: FreeBSD Net Message-ID: <20120801221240.GA24976@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.1i Subject: 0 frame length? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Aug 2012 22:12:40 -0000 Hi Folks, On a Dell R610 system, I've been tracking down some nework issues and ran across this in a tcpdump: 0000 84 2b 2b fd be 2e f0 4d a2 08 c4 13 08 00 45 00 .++....M ......E. 0010 00 00 f0 2a 40 00 40 06 00 00 0a 18 09 ee 0a 18 ...*@.@. ........ 0020 1e 08 58 57 14 02 5e 30 ea dc 61 84 62 b3 80 18 ..XW..^0 ..a.b... 0030 08 00 42 10 00 00 01 01 08 0a 1e 67 b2 58 dc 56 ..B..... ...g.X.V 0040 81 12 4e 45 54 50 41 43 4b 04 00 00 00 00 00 00 ..NETPAC K....... .... additional packet data offset 0x10 should be the frame length - not 0. This only seems to happen in packets being sent from this system/interface. Corresponding interface: bce0: flags=8943 metric 0 mtu 1500 options=c01bb ether f0:4d:a2:08:c4:13 inet 10.24.9.238 netmask 0xffff0000 broadcast 10.24.255.255 media: Ethernet autoselect (1000baseT ) status: active 8.2-RELEASE Wireshark reports: Bogus IP len (0, less than header length 20) In googling, I've seen comments about lro/tso & the *csum options. I have those set to off for the next time the systems get rebooted. The firmware is also slightly out-of-date and I'll probably update that also after finding out what the updates target. Does anyone have any ideas what the problem might be, or place I might want to look? I have a 9.1 system being put in to run some comparison benchmarks against to see if the same problem occurs. Thanks! John