[f-nsp] mac address forging !

[iVAN G]

hi,

I'm just reading the docs of the FastIron and saw there is
MAC based Radius auth. So far so good, but how did u protect from MAC
address forging ? If u have the following situation :

FastIron <---> noname-switch <----> user

In fact I want to achieve a secure way to assign IP address 
to the users and block any attempt from them to forge IP and/or MAC address.


PS. If u point me to solution for the same situation with  Extreme
please tell me it too..