Vulnerability Development mailing list archives

Re: switch jamming


From: ALoR <Alor () iol it>
Date: Thu, 31 Jan 2002 17:56:56 +0100

At 08.15 31-01-2002, you wrote:

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.

this protection is useless if you use Arp poisoning without spoofing your mac address. since the targets are the arp cache of the victims and not the switch itself, the port security feature can't block "fake arp replies" with "legal" mac address. then, when the cache are poisoned, all the packets have the right source mac address and the switch is happy about it ;)

bye bye

   --==> ALoR <==---------------------- -  -   -

 ettercap project : http://ettercap.sourceforge.net
 e-mail: alor (at) users (dot) sourceforge (dot) net


Current thread: