An attack that attempts to make a computer or servers resource unavailable

Flood Attack

Attempts to send more packets to a server than what it can handle
Protection: Flood Guards, Timeout, IDS

Ping Flood

Server is sent too many ping (ICMP echo) packets

SYN Flood

Attacker initiates multiple TCP sessions but never completes the three-way handshake

Permanent Denial of Service (PDoS)

An attack which exploits a security flaw by re-flashing the firmware, permanently breaking the networking device

Fork Bomb

A large number of processes is created to use up a computers available processing power

Distributed Denial of Service (DDoS)

Many machines are used to launch an attack against a single server to cause denial of service condition

DNS Amplification Attack

Allows attacker to initiate DNS requests from a spoofed IP address to flood a website

Prevention Measures

Blackhole/Sinkhole

Send the traffic from the attacker to non-existent IP addresses

IPS (Intrusion Prevention System)

Can detect small scale attacks and stop them

Elastic Cloud Infrastructure

Scale-up resources based on the traffic