From owner-freebsd-questions Thu Mar 19 14:20:05 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA15519 for freebsd-questions-outgoing; Thu, 19 Mar 1998 14:20:05 -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 OAA15404 for ; Thu, 19 Mar 1998 14:19:49 -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 QAA02905; Thu, 19 Mar 1998 16:19:25 -0600 (CST) Date: Thu, 19 Mar 1998 16:19:24 -0600 (CST) From: "Matthew D. Fuller" To: GLEN.W.MANN@monsanto.com cc: freebsd-questions@FreeBSD.ORG Subject: Re: arp/IP to ethernet addresses In-Reply-To: <"0319194046-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 19 Mar 1998 GLEN.W.MANN@monsanto.com wrote: > Hello! > > On the network at work, we would like the ability to match ethernet > addresses (e.g., 00:a0:24:12:34:56) to IP addresses. Dynamically? Or once-over? For what purpose, if I may ask? > The output for `arp -a' is confusing. It shows more IP addresses than > there are hosts in our DNS namedb tables, but not a full listing of > all the machines on the network. What other than explicit action, > updates the arp tables? Some time ago, `arp -a' showed me many more > entries, perhaps all the machines on the network. Is there a way to > cause the translation tables to be more complete? I'm not sure exactly what you're saying here. The arp tables should hold every MAC address that the host has talked to (fairly recently) on the local network, with no routers in between. If they haven't talked, there's no MAC address stored. > If I build a script to send pings (one per) to each possible IP > address on the net, the arp table is built. Is this a good idea? Might be better to ping the broadcast address once. Unless is breaks your network with the load, I can't imagine it's necessarily a *bad* idea. Doesn't mean it's *good*, but... > The man pages say the arp stuff works with 10Mbit ethernet, though it > seems to work with 100Mbit as well. I guess the man pages are > outdated? Never thought of it that way. I always thought of arp as a function of Ethernet, regardless of speed. *shrug* *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* | 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