NEWS

July 21, 2025

by Tega Akuruli

• #ddosattacks

Protecting Applications Against DDoS Attacks 

Distributed Denial of Service (DDoS) attacks try to overwhelm your server, app, or network by flooding it with traffic from many sources. This can make it unusable for your users. If you run an e-commerce site, SaaS product, or API, a DDoS attack can disrupt your operations in just minutes. 

This article explains how DDoS works, the types of attacks, and the defense measures that developers and system designers should apply. 

Types of DDoS Attacks 

1. Volume-Based Attacks 

• Goal: Use up all available bandwidth. 
• Example: UDP floods, ICMP floods, amplification attacks (DNS, NTP). 
• Impact: Causes network saturation. 

2. Protocol Attacks 

• Goal: Use up server resources by taking advantage of protocol weaknesses.
• Example: SYN floods, Ping of Death.
• Impact: Can crash CPU, RAM, and the server itself. 

3. Application Layer Attacks 

• Goal: Overwhelm specific endpoints like login, search, or checkout.
• Example: HTTP GET/POST floods, slowloris.
• Impact: Takes up resources in app logic, such as the database and memory. 

Signs You’re Under a DDoS Attack 

• Unusually high traffic from similar IPs or locations. 
• Slowed application performance or complete unresponsiveness. 
• Increase in CPU or bandwidth usage without growth in user activity. 
• Alerts from cloud/CDN or monitoring services. 

Best Practices to Prevent and Reduce DDoS Attacks 

1. Use a Web Application Firewall (WAF) 

WAF blocks known attack patterns. Services like Cloudflare, AWS WAF, or Imperva offer rules to filter out harmful traffic. 

2. Enable Rate Limiting 

Control the number of requests a user can make per second or minute. Implement this in the app layer using options like Express middleware, Nginx limit_req, or Django throttling. 

// Example in Express.js 
app.use(rateLimit({
  windowMs: 60 * 1000, // 1 minute 
  max: 100 // limit each IP 
}));

3. Use a Content Delivery Network (CDN)

• CDNs such as Cloudflare, Akamai, and Fastly absorb and filter traffic at edge nodes, keeping it away from your origin server.
• They also cache static assets and apply filtering rules based on location.

4. Geo-IP and Bot Filtering

• Block or challenge suspicious regions or IPs using CAPTCHA or two-factor authentication.
• Tools like Fail2Ban or bot protection services like Google reCAPTCHA and hCaptcha can help. 

5. Autoscaling Infrastructure

• Use cloud features to automatically add more servers when needed.
• Platforms like AWS Auto Scaling Groups and Google Cloud Instance Groups can assist with this. 

6. Monitor in Real Time

• Tools like Prometheus with Grafana, Datadog, and New Relic can help track traffic patterns.
• Set up alerts for unusual spikes in traffic or CPU load.

7. Upstream Protection 

• Collaborate with your ISP or hosting provider to filter traffic upstream.
• Some offer DDoS scrubbing services like AWS Shield Advanced and Azure DDoS Protection. 

Incident Response Strategy 

1. Identify: Use logs to find out the type and source of the attack. 
2. Mitigate: Activate WAF rules, rate limiting, or geo-blocking. 
3. Communicate: Inform internal teams and external users as necessary. 
4. Recover: Analyze the impact and improve protection for the future.

DDoS attacks can affect not just large corporations but also small startups and APIs. As a developer or DevOps engineer, planning ahead with scalable infrastructure and multiple layers of defense is essential. Remember that preventing an attack is cheaper than dealing with downtime.