Skip site navigation (1)Skip section navigation (2)
Date:      15 Aug 2002 09:27:56 -0500
From:      Kirk Strauser <kirk@strauser.com>
To:        freebsd-questions@freebsd.org
Subject:   Re: tool to derive ip from mac address of a remote box?
Message-ID:  <87d6skkxhv.fsf@pooh.int>
In-Reply-To: <200208142056.45333.mark.rowlands@minmail.net>
References:  <200208142056.45333.mark.rowlands@minmail.net>

next in thread | previous in thread | raw e-mail | index | archive | help

At 2002-08-14T18:56:45Z, Mark Rowlands <mark.rowlands@minmail.net> 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




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?87d6skkxhv.fsf>