Difference Between DoS and DDoS Attacks

Introduction

The modern age of technology is seeing a rise in the number of cyber-attacks, with DoS and DDoS attacks being the most popular forms of such attacks. The purpose of such attacks is to cause a website or network to become unavailable to its intended users by flooding it with an excessive amount of traffic or requests, resulting in an overload and subsequent crash. Regardless of the common goal of these two forms of attacks, there exists a significant difference between DoS and DDoS attacks.

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What is DoS Attack?

A Denial-of-Service attack, or DoS, occurs when one computer floods another with so much data that it crashes it. By flooding the server with requests, this attack may take down any website hosted on the internet.

The attacker uses a single computer or device to send malicious packets or data to the target system, exploiting its vulnerabilities or exhausting its resources. As a result, the target system cannot process legitimate requests from normal users and may crash or slow down significantly.

Here are some examples of DoS attacks –

• Buffer overflow attacks: The attacker sends more data than the target system can handle, causing it to overflow its memory buffer and crash.
• Flooding attack: The attacker sends many requests or packets to the target system, consuming its bandwidth, CPU, memory, or disk space.

What is a DDoS attack?

A Distributed Denial of Service or DDoS attack occurs when multiple devices overload a server, service, or network with an excessive amount of network traffic and, as a result, make it inaccessible to the client.

It’s like an unexpected traffic jam that blocks the road and prevents regular traffic from moving. A DDoS attack can generate much more traffic and requests than a DoS attack, making it harder to detect and stop. It can also target different layers of the network layers, such as the application layer, the transport layer, or the network layer.

Below we have given some examples of DDoS attacks –

• Application layer attacks: The attacker sends requests that act as normal users to the target system’s application layer, such as HTTP, DNS, or SMTP, exhausting its processing power and logic.
• Protocol attacks: The attacker exploits weaknesses or flaws in the network protocols that the target system uses, such as TCP, UDP, or ICMP, causing it to malfunction or consume resources unnecessarily.

Difference between DoS and DDoS attack

These are the major differences between DoS and DDoS attacks. Let’s understand these differences in detail. The main difference between the two attacks is that in the case of a DoS attack, a single device is used to carry out the attack on the client, and in the case of a DDoS attack, multiple devices are used to carry out the attack.

Below we have discussed some of the common difference between DoS and DDoS attacks based on different factors.

• Traffic Volume: DDoS attacks may rapidly overload a server and go undetected because they use several computers in different locations to simultaneously send large volumes of data. In the case of DoS attacks, only a single computer is utilized to send large volumes of data to the client side.
• Manner of Execution: DDoS attack utilizes a command-and-control (C&C) server to organize multiple hosts that have been compromised with spyware or malware (bots). Meanwhile, a DoS attack is frequently executed from a single device utilizing a script or software.
• Tracing of Source: It is considerably more challenging to track the origin of the DDoS attack as it uses a botnet, thereby leading to more damage. Whereas one can trace the origin of a DoS attack.
• Ease of Detection: DoS attack originates from a single location; it is relatively straightforward to identify and subsequently terminate the associated network connection. In reality, a firewall has the capability to accomplish this task. On the other hand, a DDoS attack originates from multiple sources, thereby hiding its point of origin.
• Speed of Attack: DDoS attacks may be launched quicker than single-site DoS attacks since they can originate from several locations. The faster rate of attack makes it harder to catch the attackers.

Now, we have a basic understanding of DoS vs DDoS. Let’s now see the similarities between the two.

Similarities between DOS and DDOS

Here are some similarities –

• Both DoS and DDoS attacks affect the regular functioning of a heavily trafficked website or network.
• Both are impactful and lead to lost revenue, damaged reputation, and increased costs of recovery and security.
• Both are aimed at draining the resources of the target website or network and making it inaccessible to authentic users.
• Both DoS and DDoS attacks are introduced in various ways, such as spoofed IP addresses, botnets, and malware.
• Both DoS and DDoS attacks can be charged under cybercrime laws if the victims know the attackers.
• Both are difficult to mitigate and fix because they last long and require sophisticated safety precautions.
• Both DoS and DDoS attacks can occur from any location.
• Both involve traffic from trusted authorities, which is difficult to detect and stop.
• Both are encouraged by numerous reasons, such as competition, political activism and extortion.

Now, let’s understand the various types of DoS and DDoS Attacks.

Types of DoS Attacks and DDoS Attacks

A wide variety of DoS and DDoS attacks can be utilized for different purposes. The goal may be to harm a company’s reputation, divert attention from other attacks, or make a political statement. Below we have explained different types of such attacks.

1. Teardrop Attacks: The attacker sends packets in smaller fragments with overlapping offsets to the target system, confusing its reassembly process and crashing it. An example of a teardrop attack is when the attacker takes extremely big data packets and splits them up into smaller pieces that the victim’s system must then reassemble. The attacker modifies the disassembly process so the victim’s system cannot recognize the pieces as part of the original packet.
2. Flooding Attacks: The attacker sends a large number of requests or packets to the target system, consuming its bandwidth, CPU, memory, or disk space. An example of a Flooding attack is when an attacker sends multiple requests acting as a client, and when the server responds, the attacker then doesn’t respond to it. The attacker repeats this process multiple times till the server becomes inaccessible. And when the real client requests the server, it either becomes busy or even crashes.
3. Volumetric Attacks: The attacker sends a massive amount of traffic to the target system, saturating its network bandwidth and preventing legitimate traffic from reaching it. It is a type of DDoS attack.
4. Application-based Attacks: An application-based attack is a form of distributed denial-of-service (DDoS) attack that specifically focuses on disrupting Layer 7 of the Open Systems Interconnection (OSI) model. An example of such an attack is the Slowloris, wherein the attacker transmits incomplete Hypertext Transfer Protocol (HTTP) requests. HTTP headers are sent at regular intervals for every request, leading to the tying up of network resources.

How to Protect from DoS Attacks and DDoS Attacks?

DoS and DDoS attacks can cause serious damage to the network and website services. Therefore, taking some preventive measures and implementing security solutions to protect yourself from these attacks is important. Some of the best steps that you can take to protect from DoS and DDoS attacks are:

• Monitor your network traffic and performance regularly and look for any unusual activity that could indicate an attack.
• Use firewalls to filter and distribute incoming traffic and block any malicious or unwanted requests.
• Use anti-virus software and update it frequently to prevent your computer from being infected by malware or viruses.
• Use cloud-based services or content delivery networks (CDNs) that can provide scalability and redundancy for your website or server and absorb excess traffic during an attack.
• Use encryption and authentication protocols to secure your data and communication channels and prevent unauthorized access or tampering.
• Implement backup and recovery plans to restore your website or server in case of an attack.

These are some ways that can protect you from DoS and DDoS attacks.

Is DDOS more dangerous than DOS?

Yes, DDoS attacks are more dangerous than DoS attacks because they come from multiple devices, whereas DoS attacks come from an individual machine. That’s why it’s difficult for teams and security products to identify the root of attacks. Additionally, if there are multiple resources and they must be located and secured to protect against persistent attacks, the confusion and risk of DDoS attacks increase.

Frequently Asked Questions

Q1 – What is the difference between a DoS and a DDoS attack?

A denial-of-service attack or DoS is a kind of attack that originates from one source. DDoS refers to a distributed denial of service attack. This suggests that more than one computer is contributing to the assault flow.

Q2 – What are the three types of DoS and DDoS attacks?

There are three main types of DoS and DDoS attacks:

• Volume-based attacks
• Protocol-based attacks
• Application-layer attacks

Q3 – What is DoS attack and example?

DoS stands for Denial-of-Service attack, which is carried out from a single computer or device by flooding it with requests that make a server or a website crash. One example of a DoS attack is when the attacker makes the server busy during a sale on an e-commerce website by sending so many requests. As a result, the original buyer or user won’t be able to access the website.

Q4 – Is DoS an active attack?

Yes, DoS is an active attack that focuses on sending multiple requests from a single machine to make a server crash or inaccessible to the client or user.

Conclusion

Both the DoS and DDoS attack pose a greater threat to the organization and businesses. In comparison, the impact of a DDoS attack is much greater when compared to a DoS attack. However, it is critical to take some steps in order to safeguard one’s organization against such attacks.

This blog covers DoS vs DDoS and different types of DoS and DDoS with some steps that can be taken to protect your system from such attacks. If you have any questions or comments, please feel free to share them below in the comment section.