Operation Manual

239
DoS Attack Type Description
SYN/SYN-ACK
Flooding
The attacker uses a fake IP address to send TCP request packets to
the Server. Upon receiving the request packets, the Server
responds with SYN-A
CK packets. Since the IP address is fake, no
response will be returned. The Server will keep on sending SYN-ACK
packets. If the attacker sends overflowing fake request packets, the
network resource will be occupied maliciously and the requests of
the legal clients will be denied.
winNuke Attack Since the Operation System with bugs cannot correctly process the
URG (Urgent Pointer) of TCP packets, the attacker sends this type of
packets to the TCP port139 (NetBIOS) of the Host with the
Operation System bugs
, which will cause the Host with a blue
screen.
Ping Of Death ICMP ECHO Request Packet whose sum of "Fragment Offset" and
"Total Length" fields in the IP header
is greater than 65535 may
cause Ping of Death attack.
As the maximum packet length of an
IPv4 packet including the IP header is 65,535 bytes, many computer
systems could not properly handle
this malformed or malicious
ICMP ECHO Request Packet. Thus, the hosts may break down or
reboot automatically when receive this kind of packet.
Table 13-1 Defendable DoS Attack Types
13.5.1 DoS Defend
On this page, you can enable the DoS Defend type appropriate to your need.
Choose the menu Network Security→DoS Defend→DoS Defend to load the following page.