From owner-freebsd-hackers Wed Mar 25 06:04:59 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA12607 for freebsd-hackers-outgoing; Wed, 25 Mar 1998 06:04:59 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from terra.Sarnoff.COM (terra.sarnoff.com [130.33.11.203]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id GAA12597 for ; Wed, 25 Mar 1998 06:04:56 -0800 (PST) (envelope-from rminnich@Sarnoff.COM) Received: (from rminnich@localhost) by terra.Sarnoff.COM (8.6.12/8.6.12) id JAA08503; Wed, 25 Mar 1998 09:04:17 -0500 Date: Wed, 25 Mar 1998 09:04:16 -0500 (EST) From: "Ron G. Minnich" X-Sender: rminnich@terra To: freebsd-hackers@FreeBSD.ORG cc: pratap singh Subject: Re: ARP REQUEST question In-Reply-To: <199803242225.OAA27230@implode.root.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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. ron To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message