From owner-freebsd-net Sat Sep 1 18:30:32 2001 Delivered-To: freebsd-net@freebsd.org Received: from elm.phenome.org (elm.phenome.org [194.153.169.3]) by hub.freebsd.org (Postfix) with ESMTP id 32E7337B408 for ; Sat, 1 Sep 2001 18:30:29 -0700 (PDT) Received: from localhost (joshua@localhost [127.0.0.1]) by localhost (8.12.0.Beta19/8.12.0.Beta19/Debian 8.12.0.Beta19) with ESMTP id f821UR2r002148; Sun, 2 Sep 2001 02:30:27 +0100 Date: Sun, 2 Sep 2001 02:30:27 +0100 (BST) From: Joshua Goodall X-X-Sender: To: Paul Chvostek Cc: Subject: Re: Gratuitous ARP (summary) In-Reply-To: <20010901124938.A41615@gahch.it.ca> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 Sat, 1 Sep 2001, Paul Chvostek wrote: > FWIW, on aliased IPs, I seem to be unable to generate the who-has arps > unless I specify the netmask. Just doing "ifconfig if0 a.b.c.d alias" > does not seem to be sufficient. But the actual value of the netmask > should not affect ARP, since ARP doesn't know about CIDR. I see the same behaviour (as predicted by Ruslan). A full ifconfig inet
netmask alias is required. > I'd still like to know how to generate a gratuitous is-at. I mean, > besides forging it in dsniff's arpspoof. I think the base system lacks the tools. You may be able to roll-your-own with appropriate ioctls, this being all ifconfig does in practise. However, none of them seem documented to perform any immediate ARP functions, this being a side-effect of their functionality at best. I think, ultimately, the only guaranteed way is to construct your own ARP packet and write it at the link layer. arping uses libnet for this. Joshua To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message