From owner-freebsd-net@FreeBSD.ORG Thu Dec 28 06:08:27 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 7E89116A412 for ; Thu, 28 Dec 2006 06:08:27 +0000 (UTC) (envelope-from stephanwehner@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.184]) by mx1.freebsd.org (Postfix) with ESMTP id 1997013C475 for ; Thu, 28 Dec 2006 06:08:26 +0000 (UTC) (envelope-from stephanwehner@gmail.com) Received: by nf-out-0910.google.com with SMTP id x37so5064176nfc for ; Wed, 27 Dec 2006 22:08:26 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=q7rWBZHHjsaTMaZi4r9+fytS78eAb3GCOqp3NcWOQXobdgmYaPfwuk6pbEfZXQmDOlDciT3uLkrVi9Wrn2MO/rmoW6I7gYgB4nvf0cJi47ftOSU1bUAeuppZEhQArVOauKUN36U8sL31SHODq3/rfSSIyaP2EEwsMWr0biP6RNw= Received: by 10.78.47.15 with SMTP id u15mr276463huu.1167286105850; Wed, 27 Dec 2006 22:08:25 -0800 (PST) Received: by 10.78.142.3 with HTTP; Wed, 27 Dec 2006 22:08:25 -0800 (PST) Message-ID: Date: Wed, 27 Dec 2006 22:08:25 -0800 From: "Stephan Wehner" To: "Matthew Hudson" In-Reply-To: <20061227221844.GA50395@gort.synoptic.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20061227221844.GA50395@gort.synoptic.org> Cc: freebsd-net@freebsd.org Subject: Re: Diagnose co-location networking problem 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: Thu, 28 Dec 2006 06:08:27 -0000 Ok, this is a little unfortunate: I can't run traceroute from the client PC (the service provider doesn't seem to like it). (Nor can I use ping) The server FreeBSD kernel doesn't support tcpdump. I should recompile it then, but not now. So I ran the netstat tests, seeing no other suggestion. Below is the output before and after "failed" accesses. If I understand, there seems no indication of lost packets. At least the problem is rather reproducible: run 'lynx -dump http://stbgo.org > /dev/null' in a loop, 15 times and a failure occurs. I also thought maybe the ssh session might be interfering, rather than showing a live connection; but without it the same occurs. Thanks a lot to all for now. Stephan # Both on client and server: $ netstat -i > /tmp/before $ netstat -s | grep -i ret >> /tmp/before ... run test .... recognize failure ... $ netstat -i > /tmp/after $ netstat -s | grep -i ret >> /tmp/after Client first. $ cat /tmp/before Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 012471498 0 0 0 8604916 36 0 1 BMRU eth0: 1500 0 - no statistics available - BMRU eth0: 1500 0 - no statistics available - BMRU lo 16436 0 429696 0 0 0 429696 0 0 0 LRU 66656 segments retransmited TCPLostRetransmit: 0 TCPFastRetrans: 1233 TCPForwardRetrans: 18 TCPSlowStartRetrans: 476 $ cat /tmp/after Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 012471903 0 0 0 8605107 36 0 1 BMRU eth0: 1500 0 - no statistics available - BMRU eth0: 1500 0 - no statistics available - BMRU lo 16436 0 429786 0 0 0 429786 0 0 0 LRU 66665 segments retransmited TCPLostRetransmit: 0 TCPFastRetrans: 1233 TCPForwardRetrans: 18 TCPSlowStartRetrans: 476 Now server $ cat /tmp/before_server Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll bge0 1500 00:0b:cd:4e:40:00 156342 3 146739 0 599 bge0 1500 65.110.18.136 df1 144448 - 145988 - - bge1* 1500 00:0b:cd:4e:41:11 0 0 0 0 0 pflog 33208 0 0 0 0 0 lo0 16384 34545 0 34545 0 0 lo0 16384 your-net localhost.stephan 34454 - 34454 - - pfsyn 2020 0 0 0 0 0 565 data packets (372083 bytes) retransmitted 38 data packets unnecessarily retransmitted 540 retransmit timeouts 156 retransmitted 0 invalid return addresses 0 no return routes $ cat /tmp/after_server Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll bge0 1500 00:0b:cd:4e:40:00 156579 3 146957 0 599 bge0 1500 65.110.18.136 df1 144671 - 146206 - - bge1* 1500 00:0b:cd:4e:41:11 0 0 0 0 0 pflog 33208 0 0 0 0 0 lo0 16384 34685 0 34685 0 0 lo0 16384 your-net localhost.stephan 34594 - 34594 - - pfsyn 2020 0 0 0 0 0 565 data packets (372083 bytes) retransmitted 38 data packets unnecessarily retransmitted 540 retransmit timeouts 156 retransmitted 0 invalid return addresses 0 no return routes