DDoS vs DoS: What’s the Difference?

• DDoS attacks involve multiple systems, while DoS attacks are launched from a single source.

• Both types of attacks can disrupt services, but DDoS attacks are often more difficult to mitigate.

Understanding DDoS and DoS Attacks  

Today, almost everything is connected to the internet, so security is more important than ever. Businesses use online platforms, but these platforms can be attacked by hackers. Two common threats are Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks. These attacks are different, and knowing how they work helps businesses protect themselves.

At first, these two attacks may seem the same. Both try to stop a service by sending too much traffic. But they are not the same. A DoS attack usually comes from one computer. A DDoS attack comes from many computers, so it is harder to stop.

Businesses need to know the difference. A DoS attack can cause problems, but it is sometimes easy to handle with simple tools. A DDoS attack is harder to stop because it comes from many places. It can shut down websites or services and cause big money loss or hurt a company’s image.

Also, not only big companies are at risk. Now, it is easier for people to rent DDoS services. This means even small businesses can be attacked. The people who do these attacks do not need to know a lot. They use groups of hacked devices, called botnets, to carry out the attack. Because of this, all businesses should be ready for both kinds of attacks.

What is a DoS Attack?  

A Denial of Service (DoS) attack occurs when a single source floods a targeted server or network with excessive traffic, overwhelming its resources and causing it to become unavailable to legitimate users. The goal of a DoS attack is to prevent users from accessing the targeted service, website, or application.

How DoS Attacks Work

A DoS attack typically involves one system that sends a massive volume of traffic or requests to a server, forcing the system to either slow down or crash. This can take several forms, such as:

• Flooding: The attacker sends an overwhelming number of requests, making it impossible for the server to handle legitimate traffic.

• Resource Exhaustion: The attacker consumes excessive resources (such as bandwidth or memory), leading to service disruption.

Despite being simpler in execution, DoS attacks can still be highly effective in disrupting operations, especially for smaller websites or businesses with limited resources.

What is a DDoS Attack?  

Distributed Denial of Service (DDoS) attacks are similar to DoS attacks but involve multiple systems working together to flood a targeted server or network. Rather than originating from a single source, a DDoS attack uses a network of compromised devices, often called a “botnet,” to launch an attack from several different locations.

How DDoS Attacks Work

In a DDoS attack, the attacker controls a network of infected devices to send simultaneous requests to the target. The sheer volume of requests overwhelms the server or network, rendering it inaccessible to legitimate users. The botnet can consist of thousands, or even millions, of devices, making it far more challenging to mitigate than a DoS attack.

Key Differences Between DDoS and DoS Attacks  

While both DoS and DDoS attacks aim to disrupt service, their key differences lie in the number of attacking sources and their impact on the target.

1. Number of Attack Sources  

• DoS: A DoS attack is initiated from a single device or system. It typically targets smaller organisations or individuals with less sophisticated security measures.

• DDoS: A DDoS attack, on the other hand, is launched from multiple devices across various locations. These devices, often compromised through malware, work in unison to overwhelm the target.

2. Scale and Complexity  

• DoS: The scale of a DoS attack is usually smaller, making it easier to mitigate with basic security measures such as firewalls or rate-limiting.

• DDoS: Due to the distributed nature of a DDoS attack, it is much larger in scale and more difficult to prevent. The multiple sources of traffic make it harder to distinguish malicious traffic from legitimate requests

 3. Detection and Mitigation   

• DoS: Because a DoS attack comes from a single source, it is easier to identify and block the offending IP address.

• DDoS: The distributed nature of a DDoS attack makes it far harder to detect and block. Attackers can disguise their origin by routing traffic through various sources, making it challenging to trace the attack back to a single point.

4. Impact on the Target  

• DoS: A DoS attack typically disrupts the service for a short period. However, it can still cause reputational damage and customer dissatisfaction.

• DDoS: DDoS attacks, especially those launched from botnets, can cause more prolonged disruptions, sometimes lasting for hours or even days. They can also target larger, more critical infrastructure, such as financial institutions or e-commerce platforms.

Why Are DDoS Attacks More Dangerous?  

Scale and Resource Requirements

One of the main reasons DDoS attacks are considered more dangerous than DoS attacks is the scale at which they operate. A DoS attack is typically limited by the capabilities of a single system, but DDoS attacks harness the power of many systems simultaneously. This not only increases the amount of traffic directed at the target but also makes it more difficult to defend against.

Botnets and Automation

DDoS attacks often use botnets. A botnet is a group of devices that have been infected with harmful software. The attacker controls these devices. They can be regular computers or smart devices like cameras and routers.

Because botnets are easy to get, DDoS attacks are now easier to do. Some people even rent out these attacks. NetScout says, “The rise of DDoS-as-a-Service has made it much easier for people with little skill to start big attacks.”

Difficulty in Mitigation

DDoS attacks are hard to stop because they come from many places at once. The attacker can keep changing the IP addresses, so it is harder to block the bad traffic.

To stop a DDoS attack, companies need special tools. These tools include traffic cleaning services or content delivery networks (CDNs) that can take in and sort the extra traffic.

Common DDoS and DoS Attack Methods  

1. Flood Attacks  

Flood attacks involve overwhelming the target’s server with an enormous amount of traffic. For instance, in a SYN flood attack, the attacker sends numerous connection requests, but never completes the handshake, leaving the server with half-open connections. This consumes the server’s resources, causing it to crash.

2. Amplification Attacks  

An amplification attack exploits a vulnerable third-party server to send large amounts of traffic to a target. The attacker sends a small request to a vulnerable server, which then sends a much larger response to the target. This type of attack can drastically increase the scale of the attack.

3. Application Layer Attacks  

Application layer attacks target specific web applications or services by exploiting vulnerabilities in the application code. These attacks typically involve sending seemingly legitimate requests, such as HTTP or HTTPS requests, to overwhelm the application and cause it to crash.

How to Protect Against DoS and DDoS Attacks  

Protecting against DoS and DDoS attacks requires a combination of strategies, including preventative measures, real-time monitoring, and mitigation tools.

1. Rate Limiting and Firewalls  

Rate limiting controls the number of requests a server can handle within a specific time frame. This helps prevent both DoS and DDoS attacks by limiting the impact of malicious requests. Firewalls can also be configured to block known attack sources or specific types of traffic.

2. Traffic Scrubbing and Content Delivery Networks (CDNs)  

Traffic scrubbing services remove malicious traffic from incoming requests before they reach the target server. CDNs can distribute traffic across a network of servers, preventing a single server from being overwhelmed.

3. Intrusion Detection Systems (IDS)  

IDS monitor network traffic for unusual patterns that may indicate an attack. These systems can help detect both DoS and DDoS attacks in their early stages, allowing for quicker responses and mitigating potential damage.

4. Cloud-Based DDoS Protection  

Cloud-based DDoS protection services, such as those offered by Cloudflare and AWS Shield, can help protect against large-scale DDoS attacks by distributing traffic and absorbing the surge in requests. These services offer real-time detection and automated mitigation.

FAQs  

1. What is the primary difference between a DoS and DDoS attack?

A DoS attack originates from a single source, while a DDoS attack uses multiple devices to flood the target.

2. Can a DDoS attack last for days?

Yes, DDoS attacks can last for extended periods, sometimes hours or even days, especially if the attacker uses a large botnet.

3. How can businesses defend against DoS and DDoS attacks?

Businesses can use firewalls, rate-limiting, traffic scrubbing, and content delivery networks (CDNs) to protect against these attacks.

4. What is a botnet in a DDoS attack?

A botnet is a network of compromised devices controlled by an attacker to launch DDoS attacks.

5. Is DDoS protection expensive?

While it can be costly, services like Cloudflare and AWS Shield offer scalable protection at various price points, making it accessible for most businesses.