From owner-freebsd-net Thu Jan 24 6:29:38 2002 Delivered-To: freebsd-net@freebsd.org Received: from mail.netmodule.com (mail.netmodule.com [195.49.111.194]) by hub.freebsd.org (Postfix) with ESMTP id 88C5937B402 for ; Thu, 24 Jan 2002 06:29:29 -0800 (PST) Received: from tigris.pacific (tigris.pacific [172.16.1.30]) by mail.netmodule.com (8.9.3/8.9.3) with ESMTP id PAA25016; Thu, 24 Jan 2002 15:29:26 +0100 Received: by tigris.pacific with Internet Mail Service (5.5.2653.19) id ; Thu, 24 Jan 2002 15:29:26 +0100 Message-ID: From: "Reto Trachsel (NetModule)" To: "'cjclark@alum.mit.edu'" , "'net@freebsd.org'" Subject: ICMP Redirect - does it not belong to the RFCs??? Date: Thu, 24 Jan 2002 15:29:25 +0100 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hi Crist and net-list > I am not sure of the reason redirects are not sent for the default > route. In your Stevens reference, he doesn't explain any reasoning for > it? As you say, the comment I quoted goes wa-ay back to before the > initial FreeBSD CVS import back to 4.4BSD or earlier. You might ask on > freebsd-net@freebsd.org as to the reasoning behind this behavior. It is described, that 4.4BSD Based Systems don't send ICMP-redirects if the next Hop is the Routers default route. In my opinion, there's no reason for this. Described into the RFC1812, a router must not send a redirect until the three conditions are met. In this case, they are. RFC1812 [Page82]: Routers MUST NOT generate a Redirect Message unless all the following conditions are met: o The packet is being forwarded out the same physical interface that it was received from, --> Met, theres only one interface in the Company Network o The IP source address in the packet is on the same Logical IP (sub)network as the next-hop IP address, and --> Met, 172.16.1.1 and 172.16.244.24 are both in the 172.16.0.0/16 Network o The packet does not contain an IP source route option. --> Met, sourcerouting is switches off on every host. Is this a part in ICMP that no belong to the RFC-Standarts, or du you know an exacter RFC? Regards Reto Trachsel To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message