Vulnerability Development mailing list archives

RE: switch jamming


From: Alexander <alex () bsdfreak org>
Date: Thu, 31 Jan 2002 11:25:22 -0500 (EST)

Hello,

        Static ARP entries can prevent this if implement on the switch
(and it is a good idea to use them on all the network devices as well).
Also, protocols such as IPSEC can strengthen any protocols tunneled
through it against manipulation or sniffing.

--
Regards,
Alexander
Editor
BSDFreak.org
e: alex () bsdfreak org
w: http://bsdfreak.org/


``Trials and tribulations of BSD users''

On Thu, 31 Jan 2002, Anthony Gruppuso wrote:

Does anybody know of any switches that can protect against this type of
attack, or is virtually every switch affected?  I imagine this is "old
news," so what have vendors done to counteract this type of activity?

-----Original Message-----
From: Sebastian Jaenicke [mailto:tsa () jaenicke org]
Sent: Wednesday, January 30, 2002 5:13 PM
To: vuln-dev () securityfocus com
Subject: Re: switch jamming


Hi,

On Wed, Jan 30, 2002 at 10:05:08PM +0000, Jan wrote:
[..]
how can i sniff upon a switched network segment ? a read some articles
about "switch jamming" and "port mirroring" but up to know i didn't
learn anything special at all.
ca some of your guys out there help me ? (i'm sure some of you can but
are you willing, too ?)


This can be achieved by flooding the switch with spoofed ARP packets
until
its internal MAC table is filled up - most switches will then revert to
"hub mode" and therefore broadcast all traffic to the network where it
can easily be sniffed.

http://www.sans.org/newlook/resources/IDFAQ/switched_network.htm should
give you some (more accurate?) information.

Sebastian
--
Sebastian Jaenicke
whois pgpkey-18AC0BE4 () whois ripe net|perl -ne's-^certif: +--&&print'
  "Object-oriented programming is an exceptionally bad idea which
   could only have originated in California." --Edsger Dijkstra



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