That could cause high cpu consumption for Radius Servers and produce much log which burden troubleshooting effort.
Session throttle feature of Cisco IOS allows us to limit number of PPPoE PADI over period of time and help to prevent this situation.
How to use:
In the Ethernet environment:
bba-group pppoe group1The above configuration cause BRAS not to answer PPPOE PADI if 10 request has passed within 60 seconds. The silent time will last for 300 seconds.
virtual-template 1
sessions per-mac throttle 10 60 300