From owner-freebsd-questions@FreeBSD.ORG Mon Jan 21 03:44:06 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id D63346C for ; Mon, 21 Jan 2013 03:44:06 +0000 (UTC) (envelope-from 22karthikreddy@gmail.com) Received: from mail-wg0-f54.google.com (mail-wg0-f54.google.com [74.125.82.54]) by mx1.freebsd.org (Postfix) with ESMTP id 6E369770 for ; Mon, 21 Jan 2013 03:44:06 +0000 (UTC) Received: by mail-wg0-f54.google.com with SMTP id fg15so3380707wgb.33 for ; Sun, 20 Jan 2013 19:44:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:mime-version:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=bHmbICP6xIyXnEHPvUy6oS85nYAZ5qDC/mEN3RbFV54=; b=nJFDzM3PXDAs6fyZ7HCrnde8258WEZNlBB438VpIngC//1CN9auGcf24Aqx+OT1xap M7dz+FpimWdJiKzMDA0xOBuJZ9BQEIdMfCLdOswQALC8aMOGs4MDZ3Q+ur3VSMn0+Rr2 f1FQtLsLpJdNJra2LALssXrYPoTpNMjgoMaQTOghedV/fuT9RE9FAr+g/LdgCfXxL+lu 53Aq2XxZykKg/jkKLeDAuH/RIs2yc0SdghV/4sIcTb6suOCvTKcSTFamKNsoJw9AadG6 vAQElEcpKYzHkd1EOVFDaTgwXA9EFxiE4EknXImKxsFFT96Z80heUhG7/5dTBvmqd9jy lz0A== X-Received: by 10.194.58.175 with SMTP id s15mr23829956wjq.31.1358739538992; Sun, 20 Jan 2013 19:38:58 -0800 (PST) MIME-Version: 1.0 Received: by 10.194.6.1 with HTTP; Sun, 20 Jan 2013 19:38:38 -0800 (PST) In-Reply-To: References: From: Karthik Reddy <22karthikreddy@gmail.com> Date: Sun, 20 Jan 2013 23:38:38 -0400 Message-ID: Subject: Re: What is the timeout of TCP in freeBSD? To: Adam Vande More Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Jan 2013 03:44:06 -0000 When I change the kern.hz to 50, the timeout is happening at 76sec. Could you please elaborate on kern.hz and how does it effect timing. On Sun, Jan 20, 2013 at 10:12 PM, Adam Vande More wrote: > On Sun, Jan 20, 2013 at 8:50 AM, Karthik Reddy <22karthikreddy@gmail.com>wrote: > >> I was doing a experiment on FreeBSD for testing TCP timeout and RTO. OS is >> being run from two different VMware versions 4.0 and 5.0. >> >> Present Scenario: VMware Player 4.0 >> I'll start a telnet session to a non-existing system in the network. When >> I >> look at the tcpdump the RTO starts at every 3 seconds and after some >> exponential backoff starts. In this scenario after 75 seconds the TCP >> gives >> up and tells me that there is no system existing with the IP and telnet >> session terminates. >> >> Next Scenario: VMware Player 5.0 >> In this scenario, I did the same but the RTO starts at 5 sec and then >> varies. In this scenario, it takes more than 120 seconds for telnet >> session >> to tell me that there is no system is available in the network. >> >> I have seen sysctl in both VM's. net.inet.tcp.keepinit = 75000 >> >> Is this problem something related to timing of the VM's or any other >> issue? >> > > What's the wallclock delta during such a test? Have you tried setting > 'kern.hz="50"' or fiddling other TC options? UP VM's tend to keep time > better than other multicore configs. > > -- > Adam Vande More -- Karthik Reddy I'm not the best, but I'm not like the Rest