From owner-freebsd-current Mon May 8 10:18:12 2000 Delivered-To: freebsd-current@freebsd.org Received: from mass.cdrom.com (adsl-63-202-176-114.dsl.snfc21.pacbell.net [63.202.176.114]) by hub.freebsd.org (Postfix) with ESMTP id CB69037B9ED for ; Mon, 8 May 2000 10:18:05 -0700 (PDT) (envelope-from msmith@mass.cdrom.com) Received: from mass.cdrom.com (localhost [127.0.0.1]) by mass.cdrom.com (8.9.3/8.9.3) with ESMTP id KAA15261; Mon, 8 May 2000 10:26:55 -0700 (PDT) (envelope-from msmith@mass.cdrom.com) Message-Id: <200005081726.KAA15261@mass.cdrom.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Rahul Dhesi Cc: Bill Fenner , freebsd-current@freebsd.org Subject: Re: gratuituous arp for multiple IP addresses In-reply-to: Your message of "Sun, 07 May 2000 19:17:54 PDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 08 May 2000 10:26:55 -0700 From: Mike Smith Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > By "gratuituous arp" I was really saying "gratuitous arp reply". > The machine needs to send a packet of the type > > arp reply 1.2.3.5 is-at 0:40:5:42:d6:de > > Rahul That won't achieve the desired result, which is to complain if someone _else_ replies to the arp request that we send. The above is achieved by virtue of sending the ARP request (anyone watching ARP messages will learn that we are the address in the "tell x.x.x.x" field). What we're trying to provoke is someone else saying x.x.x.x is-at xx.xx.xx.xx.xx.xx, which will result in a console message on our system informing the administrator that someone else is already using that IP address. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message