With the development of the Internet, the content distribution network (CDN) plays an important role in providing fast and stable content transmission. This article will introduce you to how to build a CDN server by yourself, which can not only improve the performance of the website, but also strengthen the defense of network attacks.

　　1. Understand the working principle of CDN: The content distribution network cached the content to at most distributed nodes. Users can obtain data from nodes closer to, thereby increasing access speed. This distributed architecture also enables CDN to share the pressure from network attacks.

　　2. Prepare server and domain name: You need one or more servers, which can be a virtual private server (VPS) or physical server for setting up CDN nodes. In addition, it is necessary to have a domain name to configure CDN CNAME records.

　　3. Select CDN software: There are many open source CDN software to choose from, such as Nginx, Varnish, etc. In this article, we take Nginx as an example to demonstrate the construction process.

　　4. Installation and configuration nginx:

　　Install Nginx on the server.

　　Configure the reverse proxy of Nginx and distribute the flow to the real server. In the nginx configuration, use the proxy_pass instruction to configure the address of the real server.

　　5. Configure cache and cache rules: Configure the cache mechanism of Nginx to cache the content into the CDN node. You can configure different cache rules according to your needs, such as specifying the cache time, the type of file that ignore the cache, etc.

　　6. Configure security measures: In order to prevent network attacks, you can take the following security measures:

　　Enable DDOS defense: Use Nginx's speed limit and connection control to slow the attack traffic.

　　Configure the firewall: Set the rules of firewall, and limits only to allow specific IP to access the CDN node.

　　Use SSL: Enable SSL/TLS encryption to ensure the security of data during transmission.

　　7. Configure CNAME record: In your domain name management panel, configure the CNAME record of the CDN node to associate the CDN domain name to your main domain name.

　　8. Test and optimize: Test the performance and stability of the CDN server. Adjust the cache rules and network topology according to the actual situation to improve performance.

　　9. Monitoring and maintenance: regularly monitor the performance of CDN nodes, track traffic and cache usage. Update server and software in time to ensure system security.

　　The self -built CDN server can not only improve the performance of the website, but also enhance the defense capabilities of network attacks. Through distributed architecture, cache mechanism and security measures, you can create a highly efficient, stable and defensive content distribution network to provide users with a better access experience. However, the construction of a CDN server involves complex technology and configuration and needs to be handled with caution.