DDoS Attack: Definition, Types, and How to Prevent It

If you are a webmaster, surely you would have often heard the term DDoS attack. In fact, this type of cyber attack is nothing new in cyberspace. Since it first appeared in 1974, DDoS has even continued to develop in terms of quality and quantity. 

Based on a report from Securelist, the number of DDoS attacks in the last quarter of 2021 increased by 52% compared to the last quarter of 2020. History also records that world-renowned companies such as Amazon Web Services, Bank of America, GitHub, Citigroup, and Cloudflare, are also inseparable from the threat of this attack.

That's why having basic knowledge about DDoS attacks is a must. Hopefully, you can prevent and overcome this attack to not harm your company. 

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What is a DDoS Attack?

Distributed Denial of Service or DDoS is a type of cyber-attack that targets websites, online services, and networks by flooding them with a lot of fake traffic. The main motive is for your server or network to be unable to accommodate this traffic, causing your website/service to go down and be inoperable.  

There are several symptoms that generally occur when you are exposed to a DDoS attack, including:

• The website, application, or service you are running suddenly becomes slow or inaccessible.
• There is unusual traffic from a certain IP address, or the visitors have a similar pattern/behaviour profile, such as the similarity of the browser version, location, and the type of device used.
• Internet connection is slow, so you have trouble accessing files or websites for a long time.
• The emergence of spam emails in large numbers.

But remember, there are times when the above symptoms can also occur due to other factors; For example, because the system administrator is undergoing a maintenance process, there is a technical problem with your connection, your device has a virus, or your website is really experiencing a surge in visitors. 

Therefore, to be more sure whether you are indeed exposed to a DDoS attack or not, it's a good idea to ask your company's professional technical team to do further analysis. If you are a Linux operating system user, you can also do the checking process through the Command Line Interface (CLI) with the help of some Linux commands.

DDoS Attack Categories

Some of the categories of DDoS attacks include:

Volumetric Attacks

Volumetric attacks are the most common DDoS attacks, accounting for 65% of them. In this category, Attackers use botnets to flood the bandwidth of your website or server with huge amounts of traffic. Several types of attacks that fall into this category include DNS amplification, UDP flood, TCP flood, and NTP amplification.   

Application Attacks

Application attacks exploit layer 7—that is, the layer where the server will accept and respond to http requests and load web pages. That is why application attacks are also known as Layer 7 attacks. This category of attacks tends to be difficult to identify and deal with because it resembles natural/organic web traffic. One type of attack that falls into this category is HTTP flood. 

Protocol Attacks

Protocol attacks (or state-exhaustion attacks) target layer 3 and layer 4 weaknesses. The trick is to make the use of server resources and network devices such as firewalls and load balancers to be excessive and exceed their capacity. Examples of attacks that fall into this category are Syn flood, Smurf DDoS, and ping of death. 

Tips to Prevent DDoS Attack

Now, let's discuss some surefire tips to prevent DDoS attacks

Regular Traffic Monitoring is a Must 

First, check your traffic activity regularly. The hope is that you will get an in-depth picture of website traffic trends and be able to distinguish between normal and high traffic. From the monitoring results, you will be able to identify the symptoms of a DDoS attack early, especially if there is suspicious visitor traffic.    

Increase Your Server Resource Capacity

Next, make sure that your website or online service is supported with a bandwidth capacity that can handle traffic spikes. For that, first know your web traffic level, then prepare extra bandwidth above that requirement as an anticipatory step. 

But keep in mind, this step is only meant to give you extra time to deal with attacks. The reason is, this method is no longer an effective solution to overcome DDoS attacks, considering the quality and quantity of attacks is also increasing day by day.

Implement Layered Protection Strategies

Don't forget to equip your server, network, or application with multiple protection systems. For example, you can strengthen your security layer by combining the use of firewalls, anti-spam, content filtering, Virtual Private Network (VPN), and other security systems.       

Conclusion

In this article, you've learned basic knowledge about DDoS attacks, from their definition and symptoms to attack categories. Also, you already know some good tips to anticipate and overcome these DDoS threats.

In short, DDoS is a type of cyber-attack that can attack anyone's website—be it personal websites, school websites, e-commerce/online shops, or even enterprise-level websites. Unfortunately, the types and motivations of these attacks also continue to evolve along with the development of technology.

If you are a webmaster, make sure the web hosting/server service you choose is also equipped with security features to prevent and overcome DDoS attacks.