Denial-of-service Attack - Symptoms and Manifestations

Symptoms and Manifestations

The United States Computer Emergency Readiness Team (US-CERT) defines symptoms of denial-of-service attacks to include:

• Unusually slow network performance (opening files or accessing web sites)
• Unavailability of a particular web site
• Inability to access any web site
• Dramatic increase in the number of spam emails received—(this type of DoS attack is considered an e-mail bomb)

Denial-of-service attacks can also lead to problems in the network 'branches' around the actual computer being attacked. For example, the bandwidth of a router between the Internet and a LAN may be consumed by an attack, compromising not only the intended computer, but also the entire network.

If the attack is conducted on a sufficiently large scale, entire geographical regions of Internet connectivity can be compromised without the attacker's knowledge or intent by incorrectly configured or flimsy network infrastructure equipment.