From owner-freebsd-questions@FreeBSD.ORG Tue Nov 28 20:15:12 2006 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 33B7516A407 for ; Tue, 28 Nov 2006 20:15:12 +0000 (UTC) (envelope-from gschultz@scriptpro.com) Received: from mail2.scriptpro.com (mail2.scriptpro.com [69.151.160.3]) by mx1.FreeBSD.org (Postfix) with ESMTP id 963B043EB7 for ; Tue, 28 Nov 2006 20:08:19 +0000 (GMT) (envelope-from gschultz@scriptpro.com) Received: from 192.168.190.236 [192.168.190.236] by mail2.scriptpro.com with XWall v3.38e ; Tue, 28 Nov 2006 14:07:46 -0600 Received: from excsvr003.scriptpro.com [192.168.190.227] by mxsvr003.scriptpro.com with XWall v3.38e ; Tue, 28 Nov 2006 14:07:45 -0600 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Date: Tue, 28 Nov 2006 14:07:45 -0600 Message-ID: <378BFA1E1FEC59458FEB168D1B4BD0075C995A@excsvr003.scriptpro.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: ping through ipfw giving unexpected results thread-index: AccTKON4JoQHBklNQACrvT48ejFTMg== From: To: Cc: Subject: ping through ipfw giving unexpected results 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 20:15:12 -0000 I am running ping.exe from a Windows 2003 Server machine through FreeBSD 4.8 running ipfw, to another Windows server. With plr=3D0, I get no = ping failures at all, and with ipfw at its defaults I get no successes, so I'm pretty sure the network is good. I configured ipfw with various packet loss rates (call it X) in one direction, _zero loss_ in the other direction. Then I ran ping for several hundred cycles. This should be sending an ICMP echo request (with X prob. of loss), and an echo reply (which should always get through). Therefore, I would expect to see a ping failure probability of X. I tried this at plr's from 0.002 up to 0.47, and did the math: ping is failing exactly (allowing for statistical variation) 1.500 times more than expected. This is too unlikely to be chance, so I figure the nice round fraction of additional failures is due to something I don't yet understand. Can anyone explain this result? Thanks. No luck searching the Internet or the FreeBSD/search sites. ------------------------------------------------------------------------ ------- FreeBSD rd_bsd 4.8-RELEASE FreeBSD 4.8-RELEASE #0: Thu Oct 2 23:31:46 CDT 2003 root@xfc_group_sim1:/usr/obj/usr/src/sys/MYKERNEL i386 -- Grant D. Schultz Senior Software Engineer ScriptPro 5828 Reeds Road Mission, KS 66202 gschultz@scriptpro.com