Methods of denial of service attacks
Smurf involves an attacker sending a large amount of Internet Control Message Protocol (ICMP) echo traffic to a set of Internet Protocol (IP) broadcast addresses.
SYN Flood, also known as the Transmission Control Protocol (TCP) SYN attack, is based on exploiting the standard TCP three–way handshake.
UDP Flood is based on UDP echo and character generator services provided by most computers on a network.