A DDoS (Distributed Denial of Service) attack is like a traffic jam on the internet. Instead of cars blocking a road, you have thousands or millions of devices sending requests to a website or online service at the same time. The goal is to overwhelm the system so real users can’t get through.
Unlike a simple DoS attack, which usually comes from one source, DDoS attacks use many compromised devices often part of a botnet. These devices can be computers, servers, or even IoT gadgets like security cameras. The attacker controls them remotely, usually without the owners even knowing.
How DDoS Attacks Work
At its core, a DDoS attack floods a network or server with so much traffic that it can’t handle the load. This can happen in different ways:
- Volume-based attacks – Send huge amounts of data to clog up bandwidth.
- Protocol attacks – Exploit weaknesses in network protocols like TCP, UDP, or ICMP.
- Application layer attacks – Target specific apps or services, often mimicking real user requests to slip past security filters.
The traffic often comes from all over the world, making it harder to block just one IP or location.
Why Attackers Do It
DDoS attacks aren’t always about money. Motivations vary:
- Ransom – Attackers demand payment to stop the attack.
- Revenge or protest – Hacktivists may target organizations to make a statement.
- Business sabotage – Competitors try to take down a rival’s service.
- Testing security – Cybercriminals probing for weaknesses.
The Impact of a DDoS Attack
The effects can be serious:
Pros (from attacker’s point of view)
- Can be launched cheaply with rented botnets.
- Hard to trace back to the original attacker.
Cons (for victims)
- Website downtime, leading to lost revenue.
- Damaged reputation and user trust.
- Extra costs for mitigation and recovery.
- Possible legal and compliance issues.
Even short outages can hurt a business especially for eCommerce, financial services, or critical infrastructure.
How to Protect Against DDoS Attacks
No defense is perfect, but layered protection can make a huge difference. Common approaches include:
- Content Delivery Networks (CDNs) – Distribute traffic across multiple servers to absorb attacks. Popular options include Cloudflare and Akamai.
- Web Application Firewalls (WAFs) – Filter malicious traffic before it hits your servers. Services like Imperva, Sucuri, and AWS WAF are widely used.
- Rate limiting – Restrict the number of requests allowed per user or IP in a set time.
- Traffic analysis tools – Use monitoring tools like Netdata or Zabbix to spot unusual patterns early.
Free CDN (Content Delivery Network) Solutions
A CDN speeds up your website by caching and serving content from a server closer to the user.
- Cloudflare: The free plan is an industry-standard for a reason. It offers unmetered DDoS mitigation, a robust CDN, and a free SSL certificate. It's an excellent choice for personal blogs and small websites.
- jsDelivr: This is a free and open-source public CDN. It's especially useful for developers who want to serve JavaScript, CSS, and other web library files directly from a fast, global network.
- Netlify: While primarily a platform for static websites, Netlify includes a global CDN and continuous deployment as part of its generous free tier, making it a great option for developers.
Free WAF (Web Application Firewall) Solutions
A WAF protects your web application from common attacks like SQL injection and cross-site scripting (XSS).
- Cloudflare WAF: The free plan from Cloudflare includes a basic WAF that protects against common exploits. It’s part of their integrated security suite and is a great entry point for WAF protection.
- ModSecurity: This is an open-source, powerful WAF that can be self-hosted. It requires technical expertise to set up and configure, but it offers a high degree of control and customization. It's often used with the OWASP Core Rule Set.
- NAXSI: An acronym for Nginx Anti-XSS and SQL Injection, this is a free and open-source WAF module for the Nginx web server. It's a low-maintenance solution that uses a "block-by-default" approach, which helps protect against unknown attacks.
Free Monitoring Tools
Monitoring tools help you keep track of your website's uptime, performance, and health.
- UptimeRobot: This is one of the most popular free monitoring services. The free plan allows you to monitor up to 50 websites or pages with checks every 5 minutes and offers email, SMS (with credits), and push notification alerts.
- StatusCake: The free plan provides uptime monitoring for up to 10 websites, with checks every 5 minutes. It also includes basic page speed monitoring and a confirmation server to reduce false alerts.
- Uptime Kuma: A self-hosted, open-source monitoring tool with a user interface similar to UptimeRobot. It can monitor HTTP(s), TCP, and DNS services and is a great option for those who want to host their own solution.
Best practice: Combine automated tools with a prepared incident response plan. If you detect an attack early, you can reroute traffic, activate extra mitigation, and notify users before it becomes a disaster.
Key Takeaways
DDoS attacks remain a major threat in 2025, especially as more devices get connected to the internet. Understanding how they work and putting the right defenses in place can keep your site or service online when it matters most.
If you manage a website or app, don’t wait for an attack to happen before acting. Even a basic combination of a CDN, WAF, and monitoring tools can go a long way toward protecting your business.