Bot attacks are one of the most common problems website owners face. Even if your resource does not process critical data, automated requests from bots can create a serious load on the server, slow down the site, or completely take it offline. From vulnerability scanning to password guessing attempts, bots operate constantly, and protection against them is a necessary step for any web project’s security.

If your site runs on a VPS or dedicated server, you have full control over security settings, including firewall configuration. In this article, we will look at simple yet effective methods to protect against bot attacks using basic tools and traffic filtering rules.

Why Bot Attacks Are Dangerous Even for Small Sites

Many small website owners mistakenly believe that bots attack only large portals or online stores. In reality, automated scanners and malicious scripts work “blindly,” checking random IP addresses in search of vulnerabilities.

The consequences of such attacks can be significant:

  • Increased server load — the site opens slowly or not at all.
  • VPS traffic and resource consumption — especially relevant for plans with limited resources.
  • Collection of vulnerability data — automated scanners identify CMS, plugin, and theme versions.
  • Password guessing (Brute Force) — attacks on the admin panel with thousands of login attempts.

Basic Tools for Bot Protection on VPS

1. Using a Firewall

A firewall is the first line of defense for your server. It blocks unwanted connections before they reach the web server (Nginx, Apache).

On VPS, the most common options are:

  • UFW (Uncomplicated Firewall) — a simple interface for iptables.
  • CSF (ConfigServer Security & Firewall) — a popular option with additional attack detection features.
  • firewalld — a more flexible tool often used in CentOS/RHEL.

Basic actions:

  1. Allow access only to necessary ports (80, 443, SSH).
  2. Block suspicious IP addresses or entire ranges.
  3. Use limits on the number of connections from a single IP.

2. Installing Fail2Ban

Fail2Ban is a tool that automatically blocks IP addresses from which suspicious activity is detected (for example, a large number of failed admin login attempts).

Key advantages:

  • Automatic detection of Brute Force attacks.
  • Flexible filters for different services (SSH, Nginx, Apache, FTP).
  • Ability to temporarily or permanently block IPs.

3. Using robots.txt and CAPTCHA

The robots.txt file helps “white-hat” search engine bots understand which pages to index. Although attackers often ignore it, it can reduce load from legitimate crawlers.

Additionally, you can add CAPTCHA to login, registration, and comment forms to filter out automated requests.

4. Request Limits (Rate Limiting)

Nginx and Apache allow limiting the number of requests from a single IP address within a given time. This effectively protects against low-level DDoS attacks and bots sending a large number of requests per second.

Example for Nginx:

nginx

limit_req_zone $binary_remote_addr zone=one:10m rate=5r/s;
limit_req zone=one burst=10;

5. Monitoring and Logging

Even the best firewall settings will be less effective without constant monitoring. Analyze your web server and system logs to quickly respond to new threats.

Useful tools:

  • GoAccess — visual log analysis for Nginx/Apache.
  • Logwatch — automatic activity reports for the server.
  • Grafana + Prometheus — full monitoring of traffic and load.

Recommendations for VPS Website Owners

  1. Use a VPS with reliable protection where you can set your own firewall rules.
  2. Regularly update your CMS, plugins, and server software.
  3. Enable two-factor authentication for control panels.
  4. Set up automatic blocking of suspicious IP addresses.
  5. Keep backups of your site for quick recovery after an attack.

Conclusion

Bot attacks are not just a problem for large websites. Even a small blog or corporate page can be targeted by automated scanners and scripts. Simple firewall configuration, installing Fail2Ban, and applying request limits can significantly reduce risks and maintain your resource’s stability.

Investing time into setting up your VPS and securing your site is a small price to pay for business safety, helping you avoid downtime and loss of customers.