From owner-freebsd-hackers Wed Mar 25 11:11:48 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA11373 for freebsd-hackers-outgoing; Wed, 25 Mar 1998 11:11:48 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from implode.root.com (implode.root.com [198.145.90.17]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA11367 for ; Wed, 25 Mar 1998 11:11:38 -0800 (PST) (envelope-from root@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.5/8.8.5) with ESMTP id LAA12206; Wed, 25 Mar 1998 11:11:34 -0800 (PST) Message-Id: <199803251911.LAA12206@implode.root.com> To: "Ron G. Minnich" cc: freebsd-hackers@FreeBSD.ORG, pratap singh Subject: Re: ARP REQUEST question In-reply-to: Your message of "Wed, 25 Mar 1998 09:04:16 EST." From: David Greenman Reply-To: dg@root.com Date: Wed, 25 Mar 1998 11:11:34 -0800 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >On Tue, 24 Mar 1998, David Greenman wrote: >> > pratap singh wrote: >> >I have a basic doubt. Every layer has a cehcksum being calculated >> >whereas the ARP frame does not have. Can anyone throw light on this >> >please. Is it because the ARP packets donot traverse the LAN boundary >> >and error rates in LAN environment are very low compared to the WAN >> >error rates???? >> All ethernet packets have a 32bit CRC, so the arps are protected by that. > >until it hits the first switch or router. Past that point the arp can be >garbaged any way you please, and the damage is undetectable. It's not an >end-to-end checksum. Do arps cross gateways and switches? in some places, >yes. Switches should be checking the CRC on inbound packets and discarding them if it is bad, so I don't see a problem. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message