Top 15 DDoS Protection Best Practices
In 2021, Amazon suffered a financial setback of around $34 million due to a one-hour system outage that led to a considerable loss in sales.
Meta suffered a loss of nearly $100M because of Facebook’s 2021 outage.
The consequences of downtime can be severe, and businesses of all sizes and governments can be affected. A DDoS attack can bring a business to a complete standstill for hours, leading to a substantial loss in revenue.
Every business has a measurable ROI associated with its online presence, and anybody can feel the pain of their service being overwhelmed as a target. How to stop DDoS attacks?
15 Best Practices for DDoS Protection
Improving website resilience against DDoS attacks is crucial to ensure uninterrupted service to your users. Here are some DDoS attack prevention techniques to help you fortify your website against DDoS attacks and handle peaks of traffic:
1. Multi-layered DDoS protection
DDoS attacks are not what they used to be 5-10 years ago. Earlier DDoS attacks were mostly Layer 3 or 4 – volumetric attacks that would attack the network or transport layers. Today, DDoS attacks are of many different types, and each type targets a different layer (network layer, transport layer, session layer, application layer) or combination of layers.
Further, attackers are finding new ways to make websites unavailable to legitimate traffic and lethal methods to exploit vulnerabilities, orchestrating highly sophisticated attacks.
Given this context, DDoS attacks cannot be prevented by simply increasing the network bandwidth or using traditional firewalls. You need a comprehensive, multi-module, and multi-layered DDoS protection solution to avoid all kinds of attacks, including application-layer DDoS attacks.
So, your solution must be scalable and have built-in redundancies, traffic monitoring capabilities, business logic flaw detection, and vulnerability management capabilities.
2. Avoid becoming a bot
One common tactic attackers use is a DDoS botnet, a network of compromised devices controlled remotely to send a large volume of traffic to the target.
Let’s say your internal website (or database or any such resource), which is not open to the public, is down due to a DDoS attack.
What’s the catch?
No employee would possibly attack their own company asset. Hence, the possible chances are that a few of the employees’ systems are compromised and are being used as bots. So, the employees must be educated on how not to be exploited.
To avoid becoming a bot, there are several things you can do:
- Keep your devices and software up to date
- Use strong and unique passwords
- Be cautious of suspicious emails and attachments
- Use a reputable anti-malware solution
- Use a reputable VPN
3. Recognize Attack Types
Your ability to identify the attack type before attackers is an integral part of the DDoS protection program. There are three frequent types of DDoS attacks that your business may encounter:
Layer 7, Application Layer or HTTP Flooding
This kind of application-layer attack targets an application with requests from multiple sources. Such attacks generate high volumes of POST, GET, or HTTP requests causing service downtime from hours to weeks. Layer 7 DDoS attack is widely used to bring down e-commerce, banking, and startup websites due to the low cost and ease of operation.
An attacker chokes the target server or network with open NTP request traffic. This traffic on Layer 3 or 4 (Network or Transport) is intensified with the payload traffic and is massive compared to the request size, hence overwhelming the service.
DNS flooding is a DDoS attack targeting the DNS (Domain Name System) servers that translate domain names into IP addresses. This attack aims to overwhelm the DNS servers with a large traffic volume, making it impossible for legitimate users to access the targeted website or online service.
By understanding each attack type’s characteristics and identifying them quickly, a DDoS protection program can respond in real-time, effectively mitigating the attack before it causes significant damage.
Identifying the attack type allows for more targeted and effective defense mechanisms, such as filtering specific traffic or blocking malicious IP addresses. Additionally, early identification of the attack type can help predict and prevent future attacks and improve overall security posture.
4. Create a DDoS Attack Threat Model
A DDoS attack threat model is a structured approach to identifying and analyzing potential risks to your online service or website from a DDoS attack.
Most new-age businesses struggle with web resources inventory to keep up with increasing growth and customer demands. New customer portals, payment gateways, application systems, marketing domains, and other resources are created and retired frequently. Are your web resources organized?
- Identify the assets you want to protect – Create a database of all the web assets you’d like to protect against DDoS attacks as an inventory sheet. It should contain network details, protocols in use, domains, number of applications, their use, last updated version, and so forth.
- Define the potential attackers- Next, define the potential attackers who might target your assets, such as hacktivists, competitors, or nation-state actors.
- Determine the attack vectors- Determine the various attack vectors an attacker could use to launch a DDoS attack, such as UDP flooding, SYN flooding, or HTTP flooding.
- Identify the attack surface- Identify the attack surface of your assets, including the network topology, hardware infrastructure, and software stack.
- Evaluate the risk level- Evaluate the risk level of each attack vector by assessing the probability of an attack occurring, the potential impact of the attack, and the likelihood of detecting and mitigating the attack.
5. Set DDoS Priority Buckets
Are all the web resources equal? What are the resources you want to be protected first?
Begin with specifying the priorities and criticality of your web resources for enhancing DDoS security. For example, business and data-centric web assets should be under the critical bucket with 24/7 DDoS protection.
- Critical: Put all the assets that can compromise business transactions or your reputation. Hackers will have a higher motivation to target these resources first.
- High: This bucket should include web assets that can hamper day-to-day business operations.
- Normal: Everything else should be included here.
A new priority bucket can be created for domains, networks, applications, and other services that are no longer used. Move them out of the business operation network as soon as possible.
6. Reduce Attack Surface Exposure
By reducing the surface area exposed to attackers, you essentially minimize the scope/ options for them to orchestrate DDoS attacks.
So, protect your critical assets, application, and other resources, ports, protocols, servers, and other entry points from direct exposure to attackers. There are a number of strategies that can be used to minimize attack surface exposure:
- You can separate and distribute assets in a network so that it’s harder to be targeted. For example, you can have your web servers in the public subnet, but the underlying database servers should be in a private subnet. Also, you can restrict access to database servers from your web servers, not other hosts.
- Even for sites accessible over the internet, you can reduce the surface area by restricting traffic to countries where your users are located.
- Leverage load balancer to protect web servers and computational resources from exposure by placing them behind it.
- Keep the application/ website clean by removing any unrelated/ irrelevant services, unnecessary features, legacy systems/ processes, etc., that attackers often leverage as points of entry.
7. Fortify the network architecture
One of the key DDoS protection best practices is to make the infrastructure and network capable of handling any thundering surge or a sudden spike in traffic. Buying more bandwidth is often suggested as an option. However, it is not a practical solution.
Onboarding on a CDN service helps you to leverage the globally dispersed network and build redundant resources capable of handling sudden volumetric traffic spikes.
8. Understand the Warning Signs
DDoS attacks include some definitive symptoms. Some common DDoS attack symptoms are spotty connectivity on the intranet, intermittent website shutdown, and internet disconnection. However, the problem is that the warning signs are similar to other problems you might have with your system—for example, viruses and slow internet connection.
If these problems are more severe and prolonged, your network will likely be under a DDoS attack, and you must take proper DDoS attack prevention actions.
Here are some warning signs that you may be under a Distributed Denial of Service (DDoS) attack:
- Unusually high traffic volume
- Slow or unresponsive website
- Network connectivity issues
- Unusual traffic patterns
- Unexpected server errors
- Unusual spikes in resource usage
To determine whether the sudden increase in website traffic is indeed a DDoS attack, this blog provides insights into conducting traffic analysis specifically for DDoS attacks.
9. Black Hole Routing
Black hole routing is a technique used to prevent Distributed Denial of Service (DDoS) attacks by dropping malicious traffic before it reaches the target network or server. This involves configuring the routers or switches to send traffic to a null interface, a “black hole,” effectively dropping the traffic.
The black hole route is typically used to block traffic from a specific IP address or subnet identified as the attack’s source.
While black hole routing is a reactive measure, it can effectively mitigate the impact of DDoS attacks. However, it’s important to note that black hole routing should be used with other proactive steps to prevent DDoS attacks.
10. Rate Limiting
Rate limiting is a technique used to prevent Distributed Denial of Service (DDoS) attacks by limiting the amount of traffic sent to a network or server. This involves limiting the number of requests or connections that can be made within a specified time frame.
When the limit is reached, the excess traffic is dropped or delayed. Rate limiting can be implemented at various levels, such as on the network, application, or DNS layers. By limiting the amount of traffic that can be sent to a network or server, rate limiting helps to prevent the overload of resources that can lead to a DDoS attack. However, it’s important to configure the rate limits carefully to avoid blocking legitimate traffic.
Measures such as Geo-access limiting, access limiting based on reputation scores, and so on based on real-time insights go a long way in preventing DDoS attacks.
11. Log Monitoring and Analysis
You might wonder how to stop DDoS attacks with log monitoring. It is one of the DDoS protection best practices to rapidly detect threats because of the data and statistics they offer regarding your web traffic. Log files contain data with ample information efficient to detect threats in real-time.
Using log analysis tools to detect DDoS threats accompany other benefits like making the DDoS remediation process fast and easy. While listing your site, traffic statistics indicate the date and time of huge spikes in traffic and which servers have been affected by the attack.
The log analyses can save you time by reducing the troubleshooting time by pre-informing the state of unwanted events. A few intelligent log management tools also provide the information required to quickly remedy and mitigate the damages of a successful DDoS attack.
12. Prepare DDoS Resiliency Plan
The business should realize that defending from DDoS attacks isn’t limited to prevention and mitigation. As the DDoS attack intends to shut down your complete operation, most DDoS protection techniques are concerned with bashing the attack down. Keep the practice of disaster recovery planning as a part of your regular operational maintenance.
The plan should focus on technical competencies and a comprehensive plan which outlines how to ensure business continuity under the pressure of a successful DDoS attack.
A disaster recovery site must be a part of your resiliency plan. The DR site, which serves as the temporary site, should have a current backup of your data. The recovery plan should also comprise critical details like the recovery approach, where critical data backups are maintained, and who is accountable for which tasks.
13. Get DDoS Protection Tools
Today, the market is flooded with tools that help you detect and defend critical web resources from DDoS attacks. It is important to understand that these tools fall under distinct categories- Detection and Mitigation.
Irrespective of the layer of attack, mitigation depends on your ability to detect fake traffic surges before they cause severe damage. Most DDoS protection tools rely on signatures and source details to warn you.
They rely on traffic hitting critical mass, which affects service availability. However, detection alone is not enough and needs manual intervention to look at the data and apply protection rules.
Can DDoS protection be automated? Many anti-DDoS solutions direct or block fake traffic based on preconfigured rules and policies.
While automatic filtering of bad traffic on the application or network layer is desirable, attackers have found newer ways of beating these policies, especially on the application layer.
You can check the must-have features of the DDoS mitigation solution here.
14. Don’t Rely on A Traditional Firewall
Even though traditional firewalls claim to have built-in anti-DDoS capabilities, they’ve only one method of DDoS blocking – the practice of indiscriminate thresholds, which blocks the particular port when its maximum threshold limit is reached.
Cybercriminals know this is an ideal way to block legitimate and malicious users. The end goal is achieved as the application and network availability is affected. Learn why traditional firewall often fails in DDoS protection here.
15. Deploy Web Application Firewall
A Web Application Firewall (WAF) is the best defense against all DDoS attacks. It thwarts malicious traffic trying to block vulnerabilities in the application. WAFs such as AppTrana backs DDoS protection solutions with round-the-clock monitoring from security experts to identify fake traffic surges and block them without affecting legitimate traffic.
You can place a WAF between the internet and the origin server. A WAF can act as a reverse proxy protecting the server from exposure by making the clients pass through them before reaching the server.
Using WAF, you can quickly implement custom rules in response to an attack and mitigate them so that the traffic is dropped before even reaching your server, thus taking an offload from the server. Depending upon where you implement WAF, it can be implemented in one of the three ways
- Network-based WAF
- Host-based WAF
- Cloud-based WAF
The Perfect Combination: WAF and DDoS Protection
Monitor Incoming Traffic
Traffic logs provide regular updates on exchanges on your application or network. Gigabytes of data flow across multiple locations, and observing it all at a single location provides an excellent view of anomalies.
Continuous monitoring of traffic flow and analysis will help your organization learn from historical attack data and attack patterns.
Moreover, centralized monitoring becomes even more critical in the application layer. Your cybersecurity team can flag traffic surges based on Anomalies, botnet signatures, and suspicious behaviour.
Behavioural based DDoS protection from WAF continuously observes and makes notes of user and entity behaviours. It then detects abnormal activity or traffic that doesn’t match every day/usual patterns.
This model uses advanced analysis, logs and reports, and threat data to identify abnormalities that might indicate malicious behaviour. According to tech experts, this method accurately detects bad actors that could threaten your system.
If your security team lacks an advanced behavioural DDoS mitigation tool like AppTrana and you’re dealing with a DDoS attack, this playbook explains simple steps on how to fix the DDoS attack and stop it in its tracks.
Cloud-Based DDoS Protection
While traditional firewalls provide only network layer protection, cloud-based DDoS protection solutions with additional filtering capabilities are vital to defending against application-layer attacks.
Cloud-based Web Application Firewalls (WAF) are not limited by the uplink limitation, ensuring virtual scalability as deployed outside your network.
Further, the off-premise cloud-based mitigation solutions are managed services and won’t demand investment in maintenance. This cost-effective solution provides better protection against application and network layer threats. You can enable the cloud-based DDoS protection solution with industry-leading security vendors as always-on or on-demand services.
DDoS protection in the cloud stops network layer attacks like UDP floods and SYN floods which are volumetric attacks built to block network pipes with forged data packets.
The always-on option is powerful enough to stop application layer attacks attempting to initiate TCP connections with an app to drain server resources. This option prevents attacks like DNS floods, HTTP floods, and low-and-slow attacks.
Threat Intelligence Feed
A threat intelligence feed is a source of information that provides insights into known and emerging threats in the context of DDoS protection. These feeds contain data about past DDoS attacks, such as the attacker’s IP addresses, the types of attacks used, and the targeted IP addresses.
This real-time intelligence lets you continuously tune your DDoS protection solutions to prevent attacks.
WAFs also use machine learning algorithms to detect and block more sophisticated attacks. These algorithms can learn from past attacks and adapt to new attack patterns over time, making them more effective at detecting and blocking previously unknown threats.
WAF with a Custom Workflow DDoS/Bot Rule
A WAF will inspect traffic at an application layer, raise alerts, and block if volumes of malicious application payloads are being sent to the application. Besides raising alerts, every block event can be a trigger to take an incrementally stronger defense posture and insights into other payloads coming from the same IP session and take more aggressive actions without worrying about False positives.
Application DDoS detection is most challenging because payloads can be crafted so that each request looks perfectly legitimate but bombards the application and its CPU cycle by sending many legitimate requests.
For example, fill up a form, post it, and force the backend application to spend CPU cycles on many concurrent requests.
To counter this, custom policies that distinguish normal human transactions from automated ones can go a long way in countering application-level DDoS attacks.