Vulnerability Development mailing list archives

Re: switch jamming


From: Blue Boar <BlueBoar () thievco com>
Date: Thu, 31 Jan 2002 08:15:24 -0800

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?


The Cisco switches at least can be secured against this, if you can
live with the inconvenience.  If you have one machine per port, you
can configure the switch to learn the first MAC address it sees,
and then not accept frames from any other address.  This means
that you can't move machines around or changes NICs without the
switch admin resetting the MAC address for the affected ports.  It also
means that you can't chain multiple machines off of any ports
configured that way, say via a hub.

                                        BB


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