Smurf DoS attackPing is a software tool that is available on
most operating systems and commonly used to check if a specified
computer is reachable. When the ping tool is executed, an ICMP
echo request packet is sent to the destination computer. If the
destination computer receives the TCP packet, it replies to
confirm the ping request. In the case of a Smurf denial-of-
service attack, the ping's packet return IP address is forged
with the IP of the targeted computer. The ping is issued to the
entire IP broadcast address. This technique causes every
computer to respond to the bogus ping packets and reply to the
targeted computer, which floods it. This technique is called a
Smurf attack because the DoS tool that is used to perform the
attack is called Smurf. One way to reduce risk of this attack is
to disable IP-directed broadcast, which is often not used or
needed. Some operating systems are configured to prevent the
computer from responding to ICMP packets.