From owner-freebsd-questions@FreeBSD.ORG Tue Nov 28 17:38:28 2006 Return-Path: X-Original-To: freebsd-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 82BD516A415 for ; Tue, 28 Nov 2006 17:38:28 +0000 (UTC) (envelope-from donald.teed@gmail.com) Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.173]) by mx1.FreeBSD.org (Postfix) with ESMTP id CD97E43CA4 for ; Tue, 28 Nov 2006 17:38:04 +0000 (GMT) (envelope-from donald.teed@gmail.com) Received: by ug-out-1314.google.com with SMTP id o2so1412931uge for ; Tue, 28 Nov 2006 09:37:44 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=P0JESW2DILbCMl7d5wzInp8Bh6XsXxVzPBeCJys2kphF0V+foKP7l2bq05Zq5p0PbHmgXpuljcMxZMIJ5wU+TPmHr0hqf6JFzkpjsLP5bqq2GH+gOD0EzUIAA502OwO9NpWQ7oN55ybvU+8L5PqR/jmDF/cBCSIik1xmQmDnSeM= Received: by 10.78.128.11 with SMTP id a11mr1143184hud.1164735463870; Tue, 28 Nov 2006 09:37:43 -0800 (PST) Received: by 10.78.159.6 with HTTP; Tue, 28 Nov 2006 09:37:43 -0800 (PST) Message-ID: Date: Tue, 28 Nov 2006 13:37:43 -0400 From: "D G Teed" To: freebsd-questions@freebsd.org In-Reply-To: MIME-Version: 1.0 References: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Re: How to go about diagnosing cause of packet loss 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: Tue, 28 Nov 2006 17:38:28 -0000 Hi, How quick I sometimes find answers after posting these types of questions. I've discovered that if ipaudit is shutdown (the promiscuous data gathering filter), the packet loss is very low. Once it starts up again at the half hour, the packet loss returns. Is there any strategy for dealing with this. I've heard of putting ipaudit on a second machine on a hub outside the firewall. But this is for a medium to large institution, so it would have to be something that can survive significant bandwidth. --Donald On 11/28/06, D G Teed wrote: > > Howdy, > > Lately we have been seeing increased packet loss > on our gateway/firewall. Running a ping plotter outside of > the firewall shows the hops are running clean. > From on or behind the firewall, we have 20 to 50% > packet loss to each hop, reaching several popular test > destinations. > > e.g.: > $ mtr -c 100 -r www.cnn.com > HOST: Loss% Snt Last Avg Best Wrst > StDev > 1. vlan-136.acadiau.ca 0.0% 100 0.4 6.1 0.4 179.9 > 26.5 > 2. silverhorde.acadiau.ca 4.0% 100 0.6 0.9 0.3 7.8 > 1.0 > 3. wfvlnsauh05-fe-0-0.aliant.ne 17.0% 100 3.4 6.3 2.6 55.0 > 8.8 > 4. hlfxns01h29-ge-4-0.aliant.ne 27.0% 100 3.6 3.8 2.5 12.4 > 1.4 > 5. rtp629049rts 15.0% 100 4.2 4.0 2.6 9.1 > 1.2 > 6. core1-halifax_POS5-0.net.bel 22.0% 100 6.2 3.7 2.6 6.2 > 0.9 > 7. core3-montrealak_pos1-1.net. 4.0% 100 24.2 26.8 20.3 126.2 > 19.2 > 8. core1-newyork83_pos_5_0_0.ne 19.0% 100 26.1 26.9 26.0 34.1 > 1.2 > 9. bx4-newyork83_pos_2_0_0.net. 31.0% 100 27.7 28.1 27.1 30.1 > 0.8 > 10. pop1-nye-P8-1.atdn.net 9.0% 100 26.2 45.2 26.2 227.4 > 48.0 > 11. bb2-nye-P0-0.atdn.net 16.0% 100 29.0 31.1 26.3 178.2 > 19.4 > 12. bb2-vie-P12-0.atdn.net 14.0% 100 33.0 46.3 32.3 206.4 > 37.6 > 13. bb2-atm-P3-0.atdn.net 18.0% 100 42.9 44.9 42.5 106.6 > 9.7 > 14. ??? 100.0 100 0.0 0.0 0.0 0.0 > 0.0 > > We have tested ipfw to allow ip from any as rule 01 > to see if logging and filtering were the issue, but it stayed > the same. It is beginning to look like the gateway server > might be saturated. > > A reboot initially cleared up the problem, but 10 minutes > later we saw the packet loss again. > > Does anyone have suggestions no how to troubleshoot/resolve > this problem? The things I'd like to measure in a short > time snap are numbers of concurrent packets, and > bandwidth. Suggestions on measuring and tweaking this > in FreeBSD (4.11) welcomed. > > --Donald > >