From owner-freebsd-net Thu Aug 9 8:49:44 2001 Delivered-To: freebsd-net@freebsd.org Received: from info.iet.unipi.it (info.iet.unipi.it [131.114.9.184]) by hub.freebsd.org (Postfix) with ESMTP id 2A76437B401; Thu, 9 Aug 2001 08:49:41 -0700 (PDT) (envelope-from luigi@info.iet.unipi.it) Received: (from luigi@localhost) by info.iet.unipi.it (8.9.3/8.9.3) id RAA06984; Thu, 9 Aug 2001 17:42:32 +0200 (CEST) (envelope-from luigi) From: Luigi Rizzo Message-Id: <200108091542.RAA06984@info.iet.unipi.it> Subject: Re: forwarding broadcast In-Reply-To: <20010809113638.A9519@enterprise.spock.org> from Jonathan Chen at "Aug 9, 2001 11:36:38 am" To: Jonathan Chen Date: Thu, 9 Aug 2001 17:42:32 +0200 (CEST) Cc: net@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL61 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 > On FreeBSD -CURRENT and -STABLE, packets to broadcast addresses are not > forwarded. For instance, if I have a FreeBSD router with interfaces I think it is correct NOT to forward local or subnet broadcasts -- it would be evil to let let an external node flood a subnet with broadcast traffic. Plus, a node has no good way (other than guessing) to know what netmask is used on an external subnet. cheers luigi > 192.168.1.1 and 192.168.2.1, and I send packets from 192.168.1.2 to > 192.168.2.255, the packets are dropped to the floor. IMO, this is wrong... > but I haven't consulted all the RFC's so I'm not sure if some standard out > there calls for it. In any case, the following patch creates a sysctl knob > to turn on or off this feature (since it can be considered a security risk > by some). I just want to ask around in case I turned out to be doing > something incredibly evil. Comments? To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message