From owner-freebsd-questions@FreeBSD.ORG Mon Jan 21 02:12:10 2013 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id E366A8EE for ; Mon, 21 Jan 2013 02:12:10 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-qc0-f177.google.com (mail-qc0-f177.google.com [209.85.216.177]) by mx1.freebsd.org (Postfix) with ESMTP id 8134D16E for ; Mon, 21 Jan 2013 02:12:10 +0000 (UTC) Received: by mail-qc0-f177.google.com with SMTP id u28so3467058qcs.22 for ; Sun, 20 Jan 2013 18:12:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=H1X0t0HNPHtWZWBXsPWLAYaKa4bdshsSmmG7oZyy0HM=; b=tyOXjWzMd1At4U0UzTzsfYlgI7fdo4wqGd+ORPx77r4H4vMZ4of2HOjc2Cqzs7qKcR zVnoY3bX+mPHxvax1EF1rxpjnaQm3v4coFNu+U1SwgTPFkGZFh+kYfvwnjJwI0b7JUlm j7wuevLPFENwWI+yTLUHEpYj5O/FbWoj1yMcXgShhjD5H3OAjWDzU/A6dTRxUljVERCo FI0femWA+hr+7KEyH1Sd8YmS9SoV/RW8TKvdDXOO4m1yq2Sgo2AaDiB8tJ2+PyNu7/Oc erCsdOQTane8sfhtf6JlAFN+Xnpz4vcCDTXDuZKNHji+N5+kFWeqx5AoQhK/kQUWGNsw MTsg== MIME-Version: 1.0 X-Received: by 10.224.111.83 with SMTP id r19mr17736472qap.39.1358734329671; Sun, 20 Jan 2013 18:12:09 -0800 (PST) Received: by 10.49.128.168 with HTTP; Sun, 20 Jan 2013 18:12:09 -0800 (PST) In-Reply-To: References: Date: Sun, 20 Jan 2013 20:12:09 -0600 Message-ID: Subject: Re: What is the timeout of TCP in freeBSD? From: Adam Vande More To: Karthik Reddy <22karthikreddy@gmail.com> 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 02:12:10 -0000 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