3Com BR-6574N manual Box of Ping of Death, and input the frequency

	box of Ping of Death, and input the frequency
	of threshold (how many packets per second,
	minute, or hour), you can also input the ‘Burst’
	value, which means when this number of ‘Ping
	of Death’ packet is received in very short time,
	this DoS prevention mechanism will be
	activated.
Discard Ping From	Check the box to activate this DoS prevention
WAN	mechanism.
Port Scan	Many kind of port scan methods are listed here,
	please check one or more DoS attack methods
	you want to prevent.
Sync Flood	Like Ping of Death, you can set the threshold
	of when this DoS prevention mechanism will be
	activated.

When you finished with the settings in this page, you can click ‘Apply’ button to save changes you made in this page, or you can click ‘Cancel’ to discard changes. After you click ‘Apply’ button, you’ll see the following messages:

Please click ‘Apply’ to save changes you made and restart the broadband router, this requires about 30 seconds and the broadband router will stop responding (this is normal and is not malfunction). You can reconnect to this broadband router and continue on other settings later.