Denial of Service attack

Definition
A denial-of-service attack (also, DoS attack) is an attack on a computer system or network that causes a loss of service to users, typically the loss of network connectivity and services by consuming the bandwidth of the victim network or overloading the computational resources of the victim system.

Methods
1. Invalid Packets
: sends packets which is malformed or fragmented in an invalid way. ping of the death.

2. Flooding
: fooding overwhelming flux of packets.
ex) ping, SYN, smurf

3. Pulsing Zombie