From owner-freebsd-questions Fri Mar 20 06:57:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA06418 for freebsd-questions-outgoing; Fri, 20 Mar 1998 06:57:05 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from shell.futuresouth.com (shell.futuresouth.com [207.141.254.20]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id GAA06402 for ; Fri, 20 Mar 1998 06:56:59 -0800 (PST) (envelope-from fullermd@futuresouth.com) Received: from shell.futuresouth.com (mail.futuresouth.com [207.141.254.21]) by shell.futuresouth.com (8.8.8/8.8.8) with SMTP id IAA25780; Fri, 20 Mar 1998 08:56:56 -0600 (CST) Date: Fri, 20 Mar 1998 08:56:56 -0600 (CST) From: "Matthew D. Fuller" Reply-To: "Matthew D. Fuller" To: GLEN.W.MANN@monsanto.com cc: freebsd-questions@FreeBSD.ORG Subject: Re: Re[2]: arp/IP to ethernet addresses In-Reply-To: <"0320144044-Re2: arp/IP to ethernet addresses"@MHS> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 20 Mar 1998 GLEN.W.MANN@monsanto.com wrote: > > (Pardon my cc:Mail!) > > The purpose is asset control verification. Basically an on-demand thing. > If ifconfig -a gives > > lp0: flags=8810 mtu 1500 > ep0: flags=8843 mtu 1500 > inet 123.456.6.80 netmask 0xfffffe00 broadcast 123.456.7.255 > inet 123.456.6.81 netmask 0xffffffff broadcast 123.456.6.81 > ether 00:a0:24:25:e4:59 > tun0: flags=8010 mtu 1500 > sl0: flags=c010 mtu 552 > ppp0: flags=8010 mtu 1500 > lo0: flags=8049 mtu 16384 > inet 127.0.0.1 netmask 0xff000000 > > then I use 123.456.7.255 as broadcast? This will cross a (rather slow) > WAN link (modem bank or something) to subnet 123.456.7. If I ping > 123.456.6.255 will I be restricted to the local subnet (123.456.6)? Well, if the interfaces are setup to see 123.456.7.255 as the broadcast address, they won't say a darn thing back if they get 123.456.6.255. I'm not sure how that would work, with the subnet divided over multiple local networks; with parts of it on different sides of a router, I'm not sure how the broadcast address will get routed. However, you won't get arp entries for systems on the other side of the router; you'd have to have a system on each (physical) network to catalog the MAC addresses. > The ping manpage talks about pinging a multicast address. Is this the same > thing? No, that's an experimental technology, having to do with referencing a given set of hosts with a single address. It might, theoretically, solve your problem, but implementing it would be a lot of trouble. But I'm not too knowledgeable about multicasting; I'll let someone else handle that one. It MIGHT be a solution, but probably a whole lot more work that it's worth. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* | FreeBSD; the way computers were meant to be | * "The only reason I'm burning my candle at both ends, is * | that I haven't figured out how to light the middle yet."| * fullermd@futuresouth.com :-} MAtthew Fuller * | http://keystone.westminster.edu/~fullermd | *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message