Draytek Vigor2100 Series User Manual page 62

Enable UDP defense
Click the checkbox to activate the UDP flood defense function. Once
the UDP packets from the Internet exceed the user-defined threshold
value, the router will be forced to discard all sequent UDP packets in
the user-defined timeout period. The default setting for threshold and
timeout are 300 packets per second and 10 seconds, respectively.
Enable ICMP flood defense
Click the checkbox to activate the ICMP flood defense function.
Similar to the UDP flood defense function, the router will discard the
ICMP echo requests coming from the Internet, once they exceed the
user-defined threshold (by default, 300 packets per second) in a
period of time (by default, 10 second for timeout).
Enable PortScan detection
Port scan attacks occur by sending packets with different port
numbers in an attempt to scanning the available services that one port
will respond. To examine such exploration behavior, please click the
checkbox to activate the Port Scan detection function in your Vigor
router. The Vigor router will identify it and report a warning message
if the port scanning rate in packets per second exceeds the
user-defined threshold value. By default, the Vigor router sets the
threshold as 300 packets per second to detect such a scanning
activity.
Block IP options
Click it to activate the Block IP options function. The Vigor router will
ignore any IP packets with IP option field appeared in the datagram
header. The IP option provides a way for hosts to send some
significant information, such as security, compartmentation, TCC
(closed user group) parameters, a series of Internet addresses,
routing messages...etc., which an outsider can analyze to learn
details about your private networks.
Firewall Setup
6-15