From owner-freebsd-net@FreeBSD.ORG Tue Dec 11 11:53:29 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 314AB16A41B for ; Tue, 11 Dec 2007 11:53:29 +0000 (UTC) (envelope-from rihad@mail.ru) Received: from mx39.mail.ru (mx39.mail.ru [194.67.23.35]) by mx1.freebsd.org (Postfix) with ESMTP id F308113C447 for ; Tue, 11 Dec 2007 11:53:28 +0000 (UTC) (envelope-from rihad@mail.ru) Received: from [217.25.20.94] (port=60905 helo=[217.25.20.94]) by mx39.mail.ru with esmtp id 1J23fv-000EFi-00 for freebsd-net@freebsd.org; Tue, 11 Dec 2007 14:53:23 +0300 Message-ID: <475E7A07.2070300@mail.ru> Date: Tue, 11 Dec 2007 15:52:39 +0400 From: rihad User-Agent: Icedove 1.5.0.14pre (X11/20071018) MIME-Version: 1.0 To: freebsd-net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: pipe buckets/hash_size 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: Tue, 11 Dec 2007 11:53:29 -0000 Hi, In FreeBSD 7.0 the defaults are: net.inet.ip.dummynet.hash_size: Default hash table size net.inet.ip.dummynet.hash_size: 64 net.inet.ip.dummynet.max_chain_len: Max ratio between dynamic queues and buckets net.inet.ip.dummynet.max_chain_len: 16 From man ipfw: "Target value for the maximum number of pipes/queues in a hash bucket. The product max_chain_len*hash_size is used to determine the threshold over which empty pipes/queues will be expired even when net.inet.ip.dummynet.expire=0." Does hash_size=64 and max_chain_len=16 mean there can only be 64*16 pipes? hash_size can be as large as 65536. Should I change their values so that the product is as large as the expected number of concurrent pipes? What happens when a pipe expires? Will it get deleted? What if more traffic appears triggering the pipe from its original ipfw rule? Thank you.