From owner-freebsd-questions@FreeBSD.ORG Thu Jan 4 23:07:28 2007 Return-Path: X-Original-To: questions@freebsd.org Delivered-To: freebsd-questions@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 978A316A40F for ; Thu, 4 Jan 2007 23:07:28 +0000 (UTC) (envelope-from bobmc@bobmc.net) Received: from smtp-out.fcibroadband.com (smtp-out.fcibroadband.com [64.119.104.17]) by mx1.freebsd.org (Postfix) with ESMTP id 5FA7113C442 for ; Thu, 4 Jan 2007 23:07:28 +0000 (UTC) (envelope-from bobmc@bobmc.net) Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-in1.fcibroadband.com (Postfix) with ESMTP id C39FF1B1736; Thu, 4 Jan 2007 18:07:27 -0500 (EST) Received: from smtp-out1 ([127.0.0.1]) by localhost (smtp-out1 [127.0.0.1]) (amavisd-new, port 10025) with SMTP id 15106-10; Thu, 4 Jan 2007 18:07:25 -0500 (EST) Received: from [192.168.1.102] (unknown [209.104.171.81]) by smtp-out.fcibroadband.com (Postfix) with ESMTP id 0921A1B173A; Thu, 4 Jan 2007 18:07:25 -0500 (EST) Message-ID: <459D8837.20502@bobmc.net> Date: Thu, 04 Jan 2007 18:05:27 -0500 From: Bob McIsaac User-Agent: Thunderbird 1.5 (X11/20060317) MIME-Version: 1.0 To: Doug Hardie References: <459CA574.4050001@bobmc.net> <68EDC705-4D55-4B69-8F97-D7901A2F5D71@lafn.org> In-Reply-To: <68EDC705-4D55-4B69-8F97-D7901A2F5D71@lafn.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: questions@freebsd.org Subject: Re: network tuning and performance troubleshooting X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Jan 2007 23:07:28 -0000 Doug Hardie wrote: > > On Jan 3, 2007, at 22:57, Bob McIsaac wrote: > >> Problem: Browser status 'looking up address' for 10 seconds for any >> web page clicked. Slashdot takes almost a minute to load. But FTP >> performance is good and running a shoutcast stream is no problem. >> Sending mail via my ISP is slow. >> >> Investigation: - "sysctl -a | grep net | less" shows a ton of >> variables >> with values assigned. Ping of nameserver assigned by dhcp takes 0.5ms. >> Ping of freebsd.org = 90ms. Nothing obvious in loader.conf or >> rc.conf (defaults). /var/log/messages has only startup info. >> >> Question: - How to solve this thorny performance problem? -Bob- > > You might want to run tcpdump and monitor one of those slow loads. > Include the timestamp in the output and see what it is doing during > that time. I would tend to suspect DNS timeouts. > > tcpdump confirms there is a ten second delay as seen on the browser. 1. there are some UDP packets to/from the nameserver. 2. nothing happens for ten seconds 3. now there is a TCP connection tcpdump: listening on vr0, link-type EN10MB (Ethernet), 17:34:07.537419 proto: UDP (17) 192.168.1.102.53032 > 192.168.1.254.domain: 45959+ A? www.google.ca. (31) 17:34:07.545218 IP proto: UDP (17) 192.168.1.254.domain > 192.168.1.102.53032: 45959 6/7/4 www.google.ca. CNAME[|domain] 17:34:07.545500 IP proto: UDP (17) 192.168.1.102.64463 > 192.168.1.254.domain: 45960+ AAAA? www.google.ca. (31) 17:34:07.868410 IP proto: UDP (17) 192.168.1.102.61375 > 192.168.1.254.domain: 48085+ PTR? 254.1.168.192.in-addr.arpa. (44) 17:34:12.545947 IP proto: UDP (17) 192.168.1.102.54649 > 192.168.1.254.domain: 45960+ AAAA? www.google.ca. (31) 17:34:12.868866 IP proto: UDP (17) 192.168.1.102.55840 > 192.168.1.254.domain: 48085+ PTR? 254.1.168.192.in-addr.arpa. (44) <<<<<<<< nothing happens for 10 seconds?? >>>>>>>>>>>> 17:34:22.546051 (tos 0x0, ttl 64, id 226, offset 0, flags [DF], proto: TCP (6), length: 64) 192.168.1.102.52363 > qb-in-f147.google.com.http: S, cksum 0x3aa5 (correct), 1762925400:1762925400(0) win 65535