DoS Attacks, which stands for Denial of Service attacks is defined as repeated electronic requests involving multiple computers sent to a server to load it down and make it unavailable.

These attacks can be in many forms and have different names, such as:

• Teardrop attack
• Degradation-of-service attacks
• Peer-to-peer attacks
• Permanent denial-of-service attacks
• Application level floods
• ICMP flood
• Nuke
• Distributed attack
• Unintentional denial of service
• Denial-of-Service Level II
• Reflected attack
• Blind Denial of Service

Symptoms of a DoS attack or DDoS attack are as follows:

Unable to access any website

Slow network performance such as opening files or getting on websites

Dramatic increase in the number of spam emails received

Inability to access a certain website