From owner-freebsd-net Tue Dec 28 17:51:40 1999 Delivered-To: freebsd-net@freebsd.org Received: from tango.SoftHome.net (tango.SoftHome.net [204.144.231.49]) by hub.freebsd.org (Postfix) with SMTP id 9187914C3C for ; Tue, 28 Dec 1999 17:51:38 -0800 (PST) (envelope-from fgont@softhome.net) Received: (qmail 3850 invoked by uid 417); 29 Dec 1999 01:58:09 -0000 Received: from unknown (HELO over) (200.51.58.184) by smtpb.softhome.net with SMTP; 29 Dec 1999 01:58:09 -0000 Message-Id: <.19991228225523.00b30b90@pop.softhome.net> X-Sender: fgont@pop.softhome.net X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Tue, 28 Dec 1999 22:56:55 -0300 To: freebsd-net@FreeBSD.ORG From: Fernando Ariel Gont Subject: Two many CRCs? Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi! I'm reading Stevens' "TCP/IP Illustrated", and have the following doubt: I don't quite understand why you have a CRC field at PPP (or at Ethernet), then one CRC field at IP and then one CRC field at the TCP layer. Why is there one CRC field in each layer, and not only one at, say, TCP? Best regards, Fernando Ariel Gont E-mail: fgont@softhome.net web site: http://members.xoom.com/gont/ --- "Con las computadoras crearemos una civilizacion de estupidos tecnologicos, y una elite se ira quedando con todo. Cuando digo elite me refiero a gente como yo, que puede leer." - Ray Bradbury, escritor To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message