From owner-freebsd-net Wed Jan 24 7:36:41 2001 Delivered-To: freebsd-net@freebsd.org Received: from dustdevil.waterspout.com (unknown [64.64.82.228]) by hub.freebsd.org (Postfix) with ESMTP id 6812737B402 for ; Wed, 24 Jan 2001 07:36:22 -0800 (PST) Received: (from csg@localhost) by dustdevil.waterspout.com (8.11.1/8.11.1) id f0O5UOm00280; Wed, 24 Jan 2001 00:30:24 -0500 (EST) (envelope-from csg) Date: Wed, 24 Jan 2001 00:30:24 -0500 From: "C. Stephen Gunn" To: Julian Elischer Cc: Patrick Bihan-Faou , Mitch Collinsworth , freebsd-net@FreeBSD.ORG Subject: Re: How to send arp request with no other traffic Message-ID: <20010124003024.A231@waterspout.com> References: <3A6E1499.D9578008@elischer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3A6E1499.D9578008@elischer.org>; from julian@elischer.org on Tue, Jan 23, 2001 at 03:32:41PM -0800 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, Jan 23, 2001 at 03:32:41PM -0800, Julian Elischer wrote: > send a hand crafted arp packet out through the nergraph > hook on the interface and let the response be put in the table. This is a side-effect of the ARP packet processing mechanism described in STD-0037. All inbound ARP packets are processed and inserted into the kernel table, before checking if a response is solicited or appropriate. The intention of the original designers of ARP was to use this mechanism to minimize the need for broadcasts on the network. I bring this up to say this is only a valid assumption on the ARP implementation in FreeBSD. I have not compared the STD-0037 recommendations with the implementation in NetBSD, and I am fairly certain that Linux _DOES_NOT_ note arp-updates from unsolicited packets. Sending spoofed ARP requests from the host in question will also require root, which inspecting the kernel routing and arp table currently doesn't. - Steve -- C. Stephen Gunn | Waterspout Communications, Inc. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message