Date: Fri, 22 Dec 2006 11:02:02 +0300 From: Ruslan Ermilov <ru@FreeBSD.org> To: Kris Kennaway <kris@obsecurity.org> Cc: Andrew Pantyukhin <infofarmer@FreeBSD.org>, current@FreeBSD.org, David Xu <davidxu@FreeBSD.org> Subject: Re: vge(4) bad checksum Message-ID: <20061222080202.GB77429@rambler-co.ru> In-Reply-To: <20061217205249.GA73132@xor.obsecurity.org> References: <cb5206420612171246q54ac783h1fd9d420b80ba84c@mail.gmail.com> <20061217205249.GA73132@xor.obsecurity.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--U+BazGySraz5kW0T Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Sun, Dec 17, 2006 at 03:52:49PM -0500, Kris Kennaway wrote: > On Sun, Dec 17, 2006 at 11:46:24PM +0300, Andrew Pantyukhin wrote: > > I'm not sure what it's all about, but with today's > > current whatever goes out my vge interface (icmp/ > > tcp/udp) has bad checksum: >=20 > This is a FAQ; it's probably using hardware checksum offloading. >=20 > Since the packet passed down to the NIC does not yet have the checksum > computed, it looks to tcpdump like the checksum is incorrect. However > if you look at the packet actually transmitted by the NIC > (e.g. tcpdump on another host), you'll see that it has the correct > checksum. >=20 Kris, you probably missed a commit by csjp@ where it was fixed. : revision 1.220 : date: 2006/11/18 23:17:22; author: csjp; state: Exp; lines: +40 -0 : Currently, drivers that support hardware offload of VLAN tag : processing are forced to toggle this functionality when the card : is put in and out of promiscuous mode. The main reason for this : is because the hardware strips the VLAN tag, making it impossible : for the tag information to show up in network diagnostic tools like : tcpdump(1). : [...] Andrey, have you been able to narrow your problem down to either this commit, my vge(4) commit (though you tested it as well before it was committed), or to FAST_IPSEC? Cheers, --=20 Ruslan Ermilov ru@FreeBSD.org FreeBSD committer --U+BazGySraz5kW0T Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (FreeBSD) iD8DBQFFi5D6qRfpzJluFF4RApBgAJwNSB6+rE9oy72GaIjggMx4my42GACfRJSp piJ+Lc+vrJumSVbBGUCzqbU= =Pewx -----END PGP SIGNATURE----- --U+BazGySraz5kW0T--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20061222080202.GB77429>