What is Denial of Service (DoS) Attack in Computer Network?

DoS (Denial of Service), as the name implies, is a type of attack that makes a system inoperable.

What is DoS in a Network?

DoS is an attack to prevent the current service state of a server or a service. An attack on a server aims to consume all the resources of that server and put it out of service.

The attacker sends a data packet at a rate that consumes server resources. Since it takes a lot of time to process the incoming data packet to the server, the server will increase its resource usage and, therefore, will be unable to respond to the users who are connecting.

In short, the purpose of an attack is to put an institution or company’s website, e-mail servers, or even telephone systems into an inoperable state. In this way, a company that cannot provide services will kidnap its new customers and deliver them to competing companies.

Such attacks are usually done over the Internet. These attacks on the Internet ensure that the server is unable to serve by depleting bandwidth.

This attack is done by only one system, but it is easy to prevent.

Who Makes DoS Attacks?

Hacker groups, governments, commercial companies, and ordinary users often carry out these attacks. Even users with basic computer knowledge can find free programs on the Internet to carry out this attack and attack a service.

DoS Attack Types

1) ICMP Flood Attack

In the ICMP Flood attack type, the network is rendered inoperable by sending fake packets to all computers on the target network. This type of attack is also known as Smurf Attack and Ping of Death.

2) SYN Flood Attack

In an SYN Flood attack, the attacker sends a packet to connect to the server, and a TCP Handshake is never completed in this attack type. It continues until you scan all open ports on the server. As a result, the ports occupied on the server cannot respond to new connection requests.

Today’s operating systems are designed to prevent this attack. If you are using an older operating system, you may need to upgrade to the new version of the operating system.

3) Buffer Overflow Attack

Buffer Overflow Attack is the most commonly used attack type. In the Buffer Overflow attack type, more fake packets are sent to a network address.

4) Smurf Attack

The Smurf Attack type uses the victim’s computer to attack the target computer, mimicking the IP address of the victim’s computer. The attacker sends too many ICMP Ping broadcast traffic to the target computer, making the attacked computer unresponsive.

Avoiding this attack is easy, and you can turn off the response to Ping requests on your router. Since the operating systems used today are also constantly updated, they will not be affected by this type of attack.

5) Fraggle Attack

The Fraggle Attack type is similar to the Smart Attack attack. Fraggle Attack uses the UDP port. To prevent this type of attack, it is recommended that you close ports 7 and 19 on the firewall.

6) Ping of Death Attack

When a packet larger than 65,535 bytes, the maximum size of a Ping of Death attack type, is sent, the target operating system may crash. The operating systems used today are not affected by this type of attack. If you are using outdated operating systems on your old computers, you can update them.

Free Programs

There are quite a few free attack programs available on the Internet. You can easily find these programs, but you may encounter severe legal penalties when you attempt to attack.

To test such programs, you can experiment in a virtual network environment without an Internet connection. Otherwise, we recommend that you do not conduct any tests on the Internet to attack any website.

1. LOIC (Low Orbit Ion Canon)
2. XOIC
3. HULK (HTTP Unbearable Load King)
4. DDOSIM-Layer 7 DDOS Simulator
5. R-U-Dead-Yet
6. Tor’s Hammer
7. PyLoris
8. OWASP DOS HTTP POST
9. DAVOSET
10. GoldenEye HTTP Denial of Service Tool
11. HOIC
12. UDP Flooder
13. RUDY
14. OWASP Switchblade
15. THC-SSL-DOS

Conclusion

In this article, we have briefly talked about Denial of Service – DoS attacks or Denial of Service. You can easily find such programs on the Internet. Thanks for following us!

But the last point to remember, whether it is a DoS or DDoS attack, is all CYBER CRIME.