From owner-freebsd-questions Thu Aug 15 7:28:10 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0524937B401 for ; Thu, 15 Aug 2002 07:28:05 -0700 (PDT) Received: from kanga.honeypot.net (kanga.honeypot.net [208.162.254.122]) by mx1.FreeBSD.org (Postfix) with ESMTP id BEE9143E6E for ; Thu, 15 Aug 2002 07:28:03 -0700 (PDT) (envelope-from kirk@strauser.com) Received: from pooh.int (mail@pooh.int [10.0.1.2]) by kanga.honeypot.net (8.12.5/8.12.5) with ESMTP id g7FERvL3072858 for ; Thu, 15 Aug 2002 09:27:57 -0500 (CDT) (envelope-from kirk@strauser.com) Received: from kirk by pooh.int with local (Exim 3.35 #1 (Debian)) id 17fLbR-00010M-00 for ; Thu, 15 Aug 2002 09:27:57 -0500 To: freebsd-questions@freebsd.org Subject: Re: tool to derive ip from mac address of a remote box? References: <200208142056.45333.mark.rowlands@minmail.net> From: Kirk Strauser Date: 15 Aug 2002 09:27:56 -0500 In-Reply-To: <200208142056.45333.mark.rowlands@minmail.net> Message-ID: <87d6skkxhv.fsf@pooh.int> Lines: 33 X-Mailer: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG At 2002-08-14T18:56:45Z, Mark Rowlands writes: > I know this is not strictly freebsd related but ......there is a dodgy > network card somewhere on my network pumping 1.5mb/s of crap..... All I > have is a mac address, how can I get an ip for it? On a related note, you can find out who made that NIC by searching: http://standards.ieee.org/regauth/oui/index.shtml For example, one of my adapters has this MAC address: "00:D0:B7:9E:BB:DD". If you go to that web page and enter the first three octets without the colons ("00D0B7"), you get: 00-D0-B7 (hex) INTEL CORPORATION 00D0B7 (base 16) INTEL CORPORATION 5200 NE ELAM YOUNG PARKWAY HF1-08 HILLSBORO OR 97124 UNITED STATES This can be *very* handy for tracking down rogue hardware. I was getting bizarre results from a server once; it was always pingable, but only accessible about 50% percent of the time. I finally noticed that the IP's MAC was flapping between two values, discovered that one of the OUIs belonged to Cisco, walked over to a little managed switch and cut the power, and promptly saw the problem disappear. OUI Is Your Friend. -- Kirk Strauser The Strauser Group - http://www.strausergroup.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message