From owner-freebsd-net@FreeBSD.ORG Mon Mar 24 09:55:36 2014 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 7A43DC64 for ; Mon, 24 Mar 2014 09:55:36 +0000 (UTC) Received: from mail-lb0-x232.google.com (mail-lb0-x232.google.com [IPv6:2a00:1450:4010:c04::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id E1DCFACF for ; Mon, 24 Mar 2014 09:55:35 +0000 (UTC) Received: by mail-lb0-f178.google.com with SMTP id s7so3396175lbd.23 for ; Mon, 24 Mar 2014 02:55:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=5RBaAxGCc74OQt5WUQ1IsEm531yEEKsMM9rbXYrPcrc=; b=mgi3zcpfRVpD/l1hkRda9uvD0O6eYgFZ07vgiiMgO1Uphx1Wj5Z1ia1CxHOP4V1S4P ii9bSuz4b1LJCmCZpiirtwkYwuPR0aMpbAWft5Bn/b33Cf315IDwmzi+1pJ6V/1dU1/g M8BfZtI+oKCVZ9P+9UUGEBMvZjR3BoG5auUXWihGnnBR5eA9uQBvAglD22GrGjx+wfiQ 44fQZYBMlA8hcPBd8EZ68wh7Ae1leM3sUpxBrOyJMwPaxkgYEW63rOEzFc0w2E7HE8Ld aMI9Q13kJ4iZJMv2Z1+PMFMtE6fuKytOoBUS2iEFAUlUaO6p+EJBy7S9Jz5Sc/8dAbaj Gphw== MIME-Version: 1.0 X-Received: by 10.152.190.135 with SMTP id gq7mr5258847lac.28.1395654933943; Mon, 24 Mar 2014 02:55:33 -0700 (PDT) Sender: rizzo.unipi@gmail.com Received: by 10.114.200.107 with HTTP; Mon, 24 Mar 2014 02:55:33 -0700 (PDT) In-Reply-To: References: Date: Mon, 24 Mar 2014 10:55:33 +0100 X-Google-Sender-Auth: GKRiDu_kNVjt-RfVuAdSon7FOlo Message-ID: Subject: Re: Handling Jumbo Packets From: Luigi Rizzo To: soumya panigrahi Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 Cc: Giuseppe Lettieri , Vincenzo Maffione , "freebsd-net@freebsd.org" X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Mar 2014 09:55:36 -0000 On Mon, Mar 24, 2014 at 10:47 AM, soumya panigrahi < soumyapanigrahi@gmail.com> wrote: > > On Mon, Mar 24, 2014 at 2:45 PM, Luigi Rizzo wrote: > >> >> >> >> On Mon, Mar 24, 2014 at 7:40 AM, soumya panigrahi < >> soumyapanigrahi@gmail.com> wrote: >> >>> Hi, >>> >>> First of all I would like to thank you all for developing an awesome >>> packet capturing framework. >>> I have been using it recently and find it very very fast and efficient. >>> >>> However off late I am trying to capture Jumbo packets on the network for >>> the following scenario's but that doesn't seem to be working. >>> >> >> the sysctl tree dev.netmap (on FreeBSD) >> or the filesystem >> /sys/module/netmap_lin/parameters >> (on Linux) >> have a number of parameters that control buffer numbers and sizes. >> In particular "buf_size" is used to allocate packet buffers and >> you can bump it up from 2048 to something larger to accommodate >> jumbo buffers. >> >> Depending on the NIC you may need to do something in the initialization >> of the NIC itself to allow sending/receiving frames larger than 1518 >> bytes, >> but I'd just try and see whether it works for you now. >> >> cheers >> luigi >> > > Thanks a lot for the quick response. > I will also try to see if we can handle Jumbo frames by tweaking the > buf_size parameter on Linux. > In addition can you advice if NetMap can de-fragment Jumbo packets that > were fragmented as IP packets by intermediate IP device because of MTU size > limitation? > no, netmap does not do fragmentation or reassembly cheers luigi --