From owner-freebsd-stable@FreeBSD.ORG Tue Aug 28 15:38:58 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 71897106566C for ; Tue, 28 Aug 2012 15:38:58 +0000 (UTC) (envelope-from norbert.aschendorff@yahoo.de) Received: from nm32-vm8.bullet.mail.bf1.yahoo.com (nm32-vm8.bullet.mail.bf1.yahoo.com [72.30.238.134]) by mx1.freebsd.org (Postfix) with SMTP id 010488FC14 for ; Tue, 28 Aug 2012 15:38:57 +0000 (UTC) Received: from [98.139.215.141] by nm32.bullet.mail.bf1.yahoo.com with NNFMP; 28 Aug 2012 15:38:57 -0000 Received: from [98.139.211.206] by tm12.bullet.mail.bf1.yahoo.com with NNFMP; 28 Aug 2012 15:38:57 -0000 Received: from [127.0.0.1] by smtp215.mail.bf1.yahoo.com with NNFMP; 28 Aug 2012 15:38:57 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.de; s=s1024; t=1346168337; bh=+OtMU8yQCAIZxtO9y7XJT9r8nwv6fSWMZEm8CFkDjoE=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:Content-Type:Content-Transfer-Encoding; b=Xa8/tWrvKksDcW98Bx7eaiGR0wmaK1DLlXB29FvhVjWRUshHOeHUSIQTeMbSV06lrd3QLmSViZ7ln9Qb8oNpL9x6jH1NDehs2JfE2qZ1kwVJ4+yLVYL/rl1gkNrqDVSxbcP9v+Dhjdv+Ci7Ff3Qokfe9Haq6QHh9K0uKOPP5GzI= X-Yahoo-Newman-Id: 159498.68753.bm@smtp215.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-5 X-YMail-OSG: BllgsjQVM1kUCL3NsLlzf_JDsboT1SU7fZpS6n3sDPBiBXY LJUoj2b0KfArtkeNe.dkSDP_ooq9NR8.ESxNpkH.AbVUrpy168aMyz1f6q_7 ODfaRpDEvfeboONBI9PbW4K8OwhQ69UhxH0AS7rCWb7evbdn2dkLW8j7DUhy tZn9MJOit9U9nET0RIg_fL6DoRAQTG0u8lSnog4P5a6WZlHy62F7Oed_1aUj puqnkij6Nr1_Ca7keOyEXztmAdy0nepkhwejlKVvLgIW9OZH55zK.oq335.a oPzAo364SZopMm48USriq90EKZ._DY.dbTMd8nU8ymrXdF_mN9cNL.5N7TYS vkAw2kDxYLuWq6Rh5f4gHjbuxb7irqTiRNzptXWHmhLLtO_1wB.aNyu9ZEIq X87oIzWrDyPn5Z79EpnxbHO1txApNn.R7pq51piL2B3IUC2KXky35HFajSKO zvZy_shf1zvWqWbX3WTfzMlimKlo3XlKLfVPADN7WtnE- X-Yahoo-SMTP: d20YFqmswBAWc4wd23BcX3DKFU.SSFWadKORXj_BQPQ- Received: from vostro-linux.goebo.site (norbert.aschendorff@85.216.84.153 with plain) by smtp215.mail.bf1.yahoo.com with SMTP; 28 Aug 2012 08:38:57 -0700 PDT Message-ID: <503CE60F.8040007@yahoo.de> Date: Tue, 28 Aug 2012 17:38:55 +0200 From: Norbert Aschendorff User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120418 Icedove/11.0 MIME-Version: 1.0 To: freebsd-stable@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: IPv4 vs. IPv6 Ethernet Performance X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Aug 2012 15:38:58 -0000 Hi, I'm using here a Gigabit Ethernet network and some UN*X machines, among others some Linux-based (Kernel 3.x) and one running FreeBSD 9.1-RC1. Using iperf (in TCP mode), the IPv6 bandwith between two Linux machines (directly attached to the same switch) is about 925 Mbit/s, IPv4 bandwith is about 935 Mbit/s. But now it gets exciting: The IPv6 bandwith between a Linux machine and the FreeBSD machine is around 450 Mbit/s (each direction). But the IPv4 bandwith between the same machines is 700 (Linux -> FreeBSD) to 920 (FreeBSD -> Linux) Mbit/s. Little table (values in Mbit/s): Configuration v6 v4 ======================================= Linux -> Linux 925 935 # <= This could be v6's 40B header # vs. v4's 20B Linux -> FreeBSD 450 700 FreeBSD -> Linux 455 920 ======================================= The FreeBSD->Linux value shows that the ethernet chip on the FreeBSD machine (it's Intel stuff on both sides, using the em(4) driver on FreeBSD) is able to send at full 1G speed. But why is IPv6 so slow? Regards, Norbert