Operation Manual

Protect Your Network
6-18
Enable TCP flag scan Click the checkbox to activate the Block TCP flag scan
function. Any TCP packet with anomaly flag setting is
dropped. Those scanning activities include no flag
scan, FIN without ACK scan, SYN FINscan, Xmas
scan and full Xmas scan.
Enable Tear Drop Click the checkbox to activate the Block Ping of Death
function. This attack involves the perpetrator sending
overlapping packets to the target hosts so that those
target hosts will hang once they re-construct the
packets. Any packets realizing this attacking activity
will be blocked by the Vigor routers.
Enable Ping of Death Click the checkbox to activate the Block Tear Drop
function. Many machines may crash when receiving
ICMP datagrams (packets) that exceed the maximum
length. To avoid this type of attack, the Vigor router is
designed to be capable of discarding any fragmented
ICMP packets with a length greater than 1024 octets.