From owner-freebsd-hackers Tue Jun 5 9: 4:54 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from imo-m01.mx.aol.com (imo-m01.mx.aol.com [64.12.136.4]) by hub.freebsd.org (Postfix) with ESMTP id 10FB637B401 for ; Tue, 5 Jun 2001 09:04:52 -0700 (PDT) (envelope-from Bsdguru@aol.com) Received: from Bsdguru@aol.com by imo-m01.mx.aol.com (mail_out_v30.22.) id h.94.150764fd (3969); Tue, 5 Jun 2001 12:04:37 -0400 (EDT) From: Bsdguru@aol.com Message-ID: <94.150764fd.284e5d14@aol.com> Date: Tue, 5 Jun 2001 12:04:36 EDT Subject: Re: How to disable software TCP checksumming? To: louie@transsys.com Cc: hackers@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: AOL 5.0 for Windows sub 139 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 In a message dated 06/05/2001 10:25:09 AM Eastern Daylight Time, louie@TransSys.COM writes: > Suspect hardware problem? Of course you should! That's why memory > systems have parity or ECC, and I/O buses are similarlly protected. At > least on real computers. Your view of the world is a bit misguided. I know of a situation a few years back where cascade switches were doing ATM to Frame Relay conversion and sending out mal-formed packets due to a bug in their reassembly procedure. Cisco routers (which pass data without checksuming and dont checksum pings) never saw a problem, but our unix boxes were complaining regularly. A similar situation occurred with cheap ethernet bridges that a service provider was using to colocate to a building across the street to uunet truncated packets with volumes over 2mb/s. Checksumming is there for a reason. You premise that "just because there are no physical errors, the data must be good" is simply defective. Bryan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message