6
Denial of Service Attack Prevention
With the expansion of the Internet we often hear about
Denial of Service (DoS) attacks harming major Web
sites. Yahoo, Amazon and even the White House
Web sites have all been shut down by DoS attacks as
publicly reported in 2000. A DoS attack is an incident in
which users or organizations are deprived of the services
they would normally expect to have operational. In the
worst cases, LAN services may be temporarily forced to
cease operations or an intruder may gain access onto the
LAN to corrupt processing resources to support other
malicious attacks.
Although DoS attacks are usually intentional and malicious,
they can happen accidentally and they can cause
major damage to LAN computers and require a great
deal of downtime. These attacks can range from buffer
overflow attacks, in which more traffic is sent to the
LAN than it can handle, to Smurf attacks, in which the
perpetrator sends an IP ping to computers on the LAN
specifying that they broadcast to a number of hosts so
there will be innumerable ping replies that flood the
LAN so it can no longer receive or distinguish valid
Internet traffic.
The Motorola Wireless Cable Modem Gateway Family
comes pre-configured with extensive features for
preventing DoS attacks. Stateful packet inspection
features monitor traffic flows in real time for both
LAN sessions and Internet access sessions. The
SBG1000 Wireless Cable Modem Gateway detects
misuse of LAN resources and flags anomalies that may,
in fact, be suspicious traffic. It can be customized so future
DoS attacks can be catalogued and added so the LAN
can be protected for the long term. It also offers blockers
for the following DoS attack types, as well as over
20 additional attack types.
• SYN flooding
• BackOrifice
• TCP hijacking
• Net Bus
• LAN attack
• Smurf
• WinNuke
• ICMP flooding
• Christmas tree
• Trojan Horse
• SYN/FIN
DMZ Hosting
A Demilitarized Zone (DMZ) is a neutral zone between
the private LAN and the public Internet. It opens up a
computer for clear, non-secure connections to the outside,
and the machine becomes vulnerable to security threats.
Wireless Cable Modem Gateway Family
The SBG1000 monitors
all incoming and outgoing packets,
applying policies
to each one while screening
for intrusion attempts.
