A Denial of Service is a cyber-attack in which the attacker with malicious aim makes the machine or network resource unavailable to its intended users by flooding the target network with heavy traffic.
The DoS attacks typically exploited the security vulnerabilities present in the network or system. The victims of DoS attacks are often high-profile organizations such as banking, commerce, government, and trade organizations.
How does a DoS attack work?
Denial of service is typically achieved by overwhelming or flooding the targeted network with a huge amount of requests with a malicious attempt to overload the system and prevent some legitimate requests from being fulfilled.
Some of the popular flood attacks include:
Buffer flow: This is the most common type of DoS attack. The concept is to send more traffic to the network than its capability.
ICMP flood: An ICMP flood is also known as ping flood, is a type of attack that sends spoofed packets of information that hit every computer in a targeted network instead of a single machine taking advantage of misconfigured network devices.
SYN flood: In this type of attack a request is sent to connect to a server but the handshake is never completed. As a result, the connected port remains occupied and unavailable to process further requests.
Another type of attack is the Distributed Denial of Service Attack(DDoS) attack. This type of attack comes from many distributed sources such as botnet DDoS attacks.
Types of DoS attacks:
Volumetric attacks: In this type of attack the entire bandwidth of the network is totally consumed which makes it unable to access resources for the authorized persons. This is usually achieved by overwhelming or flooding the network’s devices such as routers, hubs, or switches with ICMP echo requests until no more bandwidth is available.
Fragmentation Attacks: Fragmentation attacks are any kind of attacks that fights with reassembling ability of the target. During this type of attack, the attacker sends manipulated packets to the target making it difficult for the target to reassemble them.
TCP-State Exhaustion Attacks: In this type of attack the attacker establishes a TCP connection and then tears down and overwhelms the stable tables which result in a DoS attack.
Application Layer Attacks: Application layer attacks are comparatively difficult to detect and address. This attack basically focuses on the layer that essentially faces the end user.
Distributed Denial of Service (DDoS) Attack:
In a DDoS attack, multiple systems target a single system with a DoS attack, and further, the targeted system is flooded from multiple locations. The DDoS attacks are comparatively harder for victims to recover than the DoS attacks.
Note: All DDoS attacks are DoS attacks but not all DoS attacks are DDoS attacks
The key difference between the DoS and DDoS attacks is that the former uses a single connection to flood the victim’s computer network offline while the latter uses multiple machines. Hence the DDoS attack is more complicated compared to DoS attacks.
What is the detection process for a DDoS attack?
A DDoS attack usually involves a high amount of traffic from a large number of machines. DDoS detection software will notice a surge in connection requests.
DDoS defense system sample connection requests randomly rather than inspecting each one. When typical DDoS strategies are detected, mitigation processes will be triggered.
Does a DDoS attack damage hardware?
The DDoS attacks are designed in a way to flood the servers, load balancers, etc. They are not meant to attack physical devices.