P-660HWP-Dx Support Notes
All contents copyright © 2007 ZyXEL Communications Corporation.
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6. What is Denials of Service (DoS) attack?
Denial of Service (DoS) attacks is aimed at devices and networks with a
connection to the Internet. Their goal is not to steal information, but to disable
a device or network so users no longer have access to network resources.
There are four types of DoS attacks:
1. Those that exploits bugs in a TCP/IP implementation such as Ping of
Death and Teardrop.
2. Those that exploits weaknesses in the TCP/IP specification such as
SYN Flood and LAND Attacks.
3. Brute-force attacks that flood a network with useless data such as
Smurf attack.
4. IP Spoofing
7.
What is Ping of Death attack?
Ping of Death uses a 'PING' utility to create an IP packet that exceeds the
maximum 65535 bytes of data allowed by the IP specification. The oversize
packet is then sent to an unsuspecting system. Systems may crash, hang, or
reboot.
8.
What is Teardrop attack?
Teardrop attack exploits weakness in the reassemble of the IP packet
fragments. As data is transmitted through a network, IP packets are often
broken up into smaller chunks. Each fragment looks like the original packet
except that it contains an offset field. The Teardrop program creates a series of
IP fragments with overlapping offset fields. When these fragments are
reassembled at the destination, some systems will crash, hang, or reboot.
9.
What is SYN Flood attack?
SYN attack floods a targeted system with a series of SYN packets. Each
packet causes the targeted system to issue a SYN-ACK response, While the
targeted system waits for the ACK that follows the SYN-ACK, it queues up all
outstanding SYN-ACK responses on what is known as a backlog queue.
