P-660HWP-Dx Support Notes
All contents copyright © 2007 ZyXEL Communications Corporation.
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SYN-ACKs are moved off the queue only when an ACK comes back or when
an internal timer (which is set a relatively long intervals) terminates the TCP
three-way handshake. Once the queue is full, the system will ignore all
incoming SYN requests, making the system unavailable for legitimate users.
10. What is LAND attack?
In a LAN attack, hackers flood SYN packets to the network with a spoofed
source IP address of the targeted system. This makes it appear as if the host
computer sent the packets to itself, making the system unavailable while the
target system tries to respond to itself.
11 What is Brute-force attack?
A Brute-force attack, such as 'Smurf' attack, targets a feature in the IP
specification known as directed or subnet broadcasting, to quickly flood the
target network with useless data. A Smurf hacker flood a destination IP
address of each packet is the broadcast address of the network, the router will
broadcast the ICMP echo request packet to all hosts on the network. If there
are numerous hosts, this will create a large amount of ICMP echo request
packet, the resulting ICMP traffic will not only clog up the 'intermediary'
network, but will also congest the network of the spoofed source IP address,
known as the 'victim' network. This flood of broadcast traffic consumes all
available bandwidth, making communications impossible.
12. What is IP Spoofing attack?
Many DoS attacks also use IP Spoofing as part of their attack. IP Spoofing
may be used to break into systems, to hide the hacker's identity, or to magnify
the effect of the DoS attack. IP Spoofing is a technique used to gain
unauthorized access to computers by tricking a router or firewall into thinking
that the communications are coming from within the trusted network. To
engage in IP Spoofing, a hacker must modify the packet headers so that it
appears that the packets originate from a trusted host and should be allowed
through the router or firewall.
