Draytek Vigor3900 User Manual page 219

Available parameters are listed as follows:
Item
Broadcast Storm
Defense
Multicast Storm Defense
Unknown Unicast Storm
Defense
Unknown Multicast
Storm Defense
Storm Filtering Rate
Refresh
Apply
4 . 5 . 2 . 2
4 . 5 . 2 . 2
In the Firewall group, click the DOS Defense and click the tab of System. You will see the
following page. The DoS Defense Engine inspects each incoming packet against the attack
signature database. Any packet that may paralyze the host in the security zone is blocked.
The DoS Defense Engine also monitors traffic behavior. Any anomalous situation violating
the DoS configuration is reported and the attack is mitigated.
Available parameters are listed as follows:
Item
Enable
Block SYN Flood
Vigor3900 Series User's Guide
Description
Click Enable to block the packets attacks coming from
broadcast storm.
Click Enable to block the packets attacks coming from
multicast storm.
Click Enable to block the packets attacks coming from
unknown unicast storm.
Click Enable to block the packets attacks coming from
unknown multicast storm.
Type a number (1~4096, unit of 64Kpbs) as for the filtering
rate.
Renew current web page.
Click it to save the configuration.
S y s t e m
S y s t e m
Description
Check the box to enable this profile.
Click Enable to activate the SYN flood defense function.
If the amount of TCP SYN packets from the Internet exceeds
the user-defined threshold value, the router will be forced to
randomly discard the subsequent TCP SYN packets within
211