From owner-freebsd-net@FreeBSD.ORG Wed Dec 27 03:14:22 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 DF1A616A40F for ; Wed, 27 Dec 2006 03:14:22 +0000 (UTC) (envelope-from stephanwehner@gmail.com) Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.187]) by mx1.freebsd.org (Postfix) with ESMTP id 7EAE813C46D for ; Wed, 27 Dec 2006 03:14:22 +0000 (UTC) (envelope-from stephanwehner@gmail.com) Received: by nf-out-0910.google.com with SMTP id x37so4686759nfc for ; Tue, 26 Dec 2006 19:14:21 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=Eeis7bqNTcv0r6K6geBOC1rrKDu0py6D4Y7CYpkCEayo7FXy9JheT7kCpe11HElwvmpgvk9R2r0Js2pl1DxOTOjuHqPj3Fr70AIGOJ9knpOT4mAYxpA3v64D6popQpjbSscNopCVbQACXokYgfJAfwy+lr9PZ7bjEvfC+5z4IDM= Received: by 10.78.18.3 with SMTP id 3mr3425720hur.1167187539891; Tue, 26 Dec 2006 18:45:39 -0800 (PST) Received: by 10.78.142.3 with HTTP; Tue, 26 Dec 2006 18:45:39 -0800 (PST) Message-ID: Date: Tue, 26 Dec 2006 18:45:39 -0800 From: "Stephan Wehner" To: freebsd-net@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Subject: 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: Wed, 27 Dec 2006 03:14:23 -0000 I just got a server and put it in a co-location. It runs RELEASE FreeBSD 6.1-RELEASE #0, pound, lighttpd and ruby on rails. Most of the times I find the server responds nicely. But periodically it doesn't respond properly when accessing its webpages: Type URL in browser, hit return, no page appears. Try again and again and after a few times it appears. Other sites are accessible during these problematic times. Also, in parallel I am connected to the server through ssh, and there are not problems with that. Even during those times when the web pages don't appear, I can type and see the result. Before installing it at the datacentre, the server was working without problems on the local network. So I am thinking the problem may be with the co-location operation. How can I make sure? How can I diagnose this? The only idea I had was to run tcpdump on my Linux client (tcpdump host stbgo.org), and indeed I can see entries lines this: 18:32:24.970139 sucrose.sugarmotor.net.34503 > vps-18-138.virtualprivateservers.ca.http: S 2468438613:2468438613(0) win 5840 (DF) 18:32:25.670135 sucrose.sugarmotor.net.34508 > vps-18-138.virtualprivateservers.ca.http: S 2493895298:2493895298(0) win 5840 (DF) 18:32:49.670152 sucrose.sugarmotor.net.34508 > vps-18-138.virtualprivateservers.ca.http: S 2493895298:2493895298(0) win 5840 (DF) [note next is almost half a minute later] 18:33:12.970162 sucrose.sugarmotor.net.34503 > vps-18-138.virtualprivateservers.ca.http: S 2468438613:2468438613(0) win 5840 (DF) 18:33:12.985071 vps-18-138.virtualprivateservers.ca.http > sucrose.sugarmotor.net.34503: S 2788301288:2788301288(0) ack 2468438614 win 65535 (DF) But I am not sure what these lines are telling me; other than "sucrose" tried a few times, and then got a response (last line). Any hints? Thanks Stephan -- Stephan Wehner > http://stephan.sugarmotor.org > http://stephansmap.org > http://www.trafficlife.com > http://www.buckmaster.ca