From owner-freebsd-net@FreeBSD.ORG Mon Mar 24 09:47:20 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 52C4D9B6 for ; Mon, 24 Mar 2014 09:47:20 +0000 (UTC) Received: from mail-pa0-x232.google.com (mail-pa0-x232.google.com [IPv6:2607:f8b0:400e:c03::232]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 27199A32 for ; Mon, 24 Mar 2014 09:47:20 +0000 (UTC) Received: by mail-pa0-f50.google.com with SMTP id kq14so5238951pab.9 for ; Mon, 24 Mar 2014 02:47:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=xg4e6I5MFW9JtFsT8lzbD1C5DZEPTjKeAamXmjq6VzE=; b=SLMNrCvsek2DF/IPI0QDgoJvsFLt4esl1k2IH/dGS1zm7mgbrDzMkqX7GlT8ulEm2m oNTiwC/1zCxdH/eVZ4cAwxus4Lh6Cj6qp4VmG+/9VpHdPOvyxZzGYOcT69y+NQu1/wVA hmhu9t2RmW8o82iCCr3jTZbL/LSdwTOQAU7rw/aZxd2iq0G696gGfOMMbmrwHZfDb4Ec CyrPqNi7PJea5fDSXf62SwAOdwntpvIJJMZRQTLQe038TvI0NeOuNVYkR6J0aUF5U7cX Q0TtsgZdtfgJYa9vosV6kkNFjgMur7RoCQ0R/MvjQ0Xh3WzZMNtx+KVHRvC3GAA92/HV XWoA== MIME-Version: 1.0 X-Received: by 10.66.12.67 with SMTP id w3mr72012514pab.29.1395654439754; Mon, 24 Mar 2014 02:47:19 -0700 (PDT) Received: by 10.70.128.9 with HTTP; Mon, 24 Mar 2014 02:47:19 -0700 (PDT) In-Reply-To: References: Date: Mon, 24 Mar 2014 15:17:19 +0530 Message-ID: Subject: Re: Handling Jumbo Packets From: soumya panigrahi To: Luigi Rizzo 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 09:47:20 -0000 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? For example a 9000 Bytes single ethernet frame was fragmented into 1516 Bytes multiple ethernet frames at IP layer. Can netmap re-assemble these fragmented ethernet frames into a single Jumbo frame before passing it the application? If so how? Thanks, Soumya > > > >> Please suggest in its present form is NetMap capable of handling the >> below scenario's w.r.t Jumbo frames? If how do we have to some special >> handling w.r.t to this? >> >> 1) Netmap is receiving un-fragmented Jumbo frame. In this case is NetMap >> capable of passing on the Jumbo packet to the user? >> 2) Netmap receving fragmented Jumbo frames. In this case is NetMap >> capable of reassembling the fragmented packets and deliver the assembled >> packet to the user? >> >> I have been stuck with this issue for some time now. A quick response >> would help a great deal. >> >> Thanks, >> Soumya Panigrahi >> > > > > -- > -----------------------------------------+------------------------------- > Prof. Luigi RIZZO, rizzo@iet.unipi.it . Dip. di Ing. dell'Informazione > http://www.iet.unipi.it/~luigi/ . Universita` di Pisa > TEL +39-050-2211611 . via Diotisalvi 2 > Mobile +39-338-6809875 . 56122 PISA (Italy) > -----------------------------------------+------------------------------- >