From owner-freebsd-hackers Wed May 30 20:36: 4 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from odin.ac.hmc.edu (Odin.AC.HMC.Edu [134.173.32.75]) by hub.freebsd.org (Postfix) with ESMTP id 5059637B424 for ; Wed, 30 May 2001 20:36:01 -0700 (PDT) (envelope-from brdavis@odin.ac.hmc.edu) Received: (from brdavis@localhost) by odin.ac.hmc.edu (8.11.0/8.11.0) id f4V3Ztq30262; Wed, 30 May 2001 20:35:55 -0700 Date: Wed, 30 May 2001 20:35:55 -0700 From: Brooks Davis To: "Louis A. Mamakos" Cc: hackers list Subject: Re: How to disable software TCP checksumming? Message-ID: <20010530203555.A23918@Odin.AC.HMC.Edu> References: <20010529144114.I19771@luke.immure.com> <20010529221107.C49875@skriver.dk> <20010529155212.M19771@luke.immure.com> <20010530045200.A1031@hades.hell.gr> <20010529235215.A60177@luke.immure.com> <20010530085155.B24096@Odin.AC.HMC.Edu> <200105310204.f4V248n15260@whizzo.transsys.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="jRHKVT23PllUwdXP" Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <200105310204.f4V248n15260@whizzo.transsys.com>; from louie@TransSys.COM on Wed, May 30, 2001 at 10:04:08PM -0400 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG --jRHKVT23PllUwdXP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 30, 2001 at 10:04:08PM -0400, Louis A. Mamakos wrote: > The TCP checksum protects more than just the contents of the packet > on the wire; it's also a (somewhat) weak check on the contents > of your packet sitting in memory, and as it's going over the bus > in your computer between memory and peripherals and for other end-to-end > sorts of issues.=20 Given that we're talking about this for >=3D1Gbps devices where all devices do hardware checksuming that argument holds little water. No one is proposing turing off checksums for everything, but instead for a set of specalized, tightly coupled applications. I certaintly wouldn't turn it off for packets traversing the internet. -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --jRHKVT23PllUwdXP Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE7FbwaXY6L6fI4GtQRAheSAJ9PZdSpwU/F7JlWWxHSpJ32i78JDgCeKf4d Dom2eMN+hCY2/8ZSeGb06nM= =e5FY -----END PGP SIGNATURE----- --jRHKVT23PllUwdXP-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message