From owner-freebsd-net@FreeBSD.ORG Wed Jul 16 21:35:31 2008 Return-Path: Delivered-To: net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0A9B7106564A for ; Wed, 16 Jul 2008 21:35:31 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail36.syd.optusnet.com.au (mail36.syd.optusnet.com.au [211.29.133.76]) by mx1.freebsd.org (Postfix) with ESMTP id 0B94C8FC1B for ; Wed, 16 Jul 2008 21:35:29 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from server.vk2pj.dyndns.org (c122-106-215-175.belrs3.nsw.optusnet.com.au [122.106.215.175]) by mail36.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id m6GLIG19012559 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 17 Jul 2008 07:18:16 +1000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.2/8.14.2) with ESMTP id m6GLIFpU048851; Thu, 17 Jul 2008 07:18:15 +1000 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.2/8.14.2/Submit) id m6GLIFB8048850; Thu, 17 Jul 2008 07:18:15 +1000 (EST) (envelope-from peter) Date: Thu, 17 Jul 2008 07:18:15 +1000 From: Peter Jeremy To: Barney Cordoba Message-ID: <20080716211815.GW62764@server.vk2pj.dyndns.org> References: <20080716115548.GJ62764@server.vk2pj.dyndns.org> <813740.41559.qm@web63912.mail.re1.yahoo.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="8D1TCnBmjJJF2KCx" Content-Disposition: inline In-Reply-To: <813740.41559.qm@web63912.mail.re1.yahoo.com> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.18 (2008-05-17) Cc: Eitan Shefi , net@freebsd.org Subject: Re: "ping" with packets larger then 25152 bytes fails. 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: Wed, 16 Jul 2008 21:35:31 -0000 --8D1TCnBmjJJF2KCx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Jul-16 12:37:59 -0700, Barney Cordoba wr= ote: >> >When I run "ping" between 2 identical FreeBSD hosts, with packets larger >> >then 25152 bytes, "ping" fails. =2E.. >Isn't this sort of like going to your auto dealer and complaining that you= get vibration at 240mph? I don't think so. There are no specific limits on the size of ICMP ECHO REQUEST or ICMP ECHO REPLY packets, therefore the only limit should be the IP packet limit (64KB). It does work with other IP stacks and with the loopback interface on FreeBSD. Poking around a bit more, the culprit looks like net.inet.ip.maxfragsperpacket - which is set to 16 by default. --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --8D1TCnBmjJJF2KCx Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkh+ZZcACgkQ/opHv/APuIeI/gCguOSfaGz2jga6wpiC7fdeCiJA Gd4An2WU3TX01gHp6m38+/+io5dALjFw =3YIb -----END PGP SIGNATURE----- --8D1TCnBmjJJF2KCx--