A Content Delivery Network (CDN) helps improve website performance by distributing content across multiple servers, allowing faster access based on a user’s geographic location. There are two primary types of CDNs based on how they handle traffic routing and content delivery:
1. CDN with Traffic Proxying (DNS-based Routing) | e.g. CloudFlare
In this type of CDN, your traffic is routed through the CDN network by configuring your domain’s DNS (Name Servers). This method filters all traffic through the CDN, and services like Cloudflare typically use this method.
How it works:
- You change the NS (Name Server) settings of your domain to point to the CDN provider’s servers.
- Once the change propagates, all web traffic is directed to the CDN, which then caches and filters content.
- The CDN can perform optimizations like caching, DDoS protection, and security filtering without you needing to alter any website content.
Advantages:
- Full traffic control: The CDN handles all incoming and outgoing requests, providing a complete optimization layer.
- Security features: With DNS-based routing, advanced security mechanisms like Web Application Firewalls (WAF), DDoS protection, and SSL encryption can be applied universally.
- No need to change URLs for images, videos, or files.
Step-by-step instructions:
- Sign up for a CDN provider that uses traffic proxying (e.g., Cloudflare).
- Log in to your domain registrar (where your domain is registered).
- Locate the DNS settings or “Name Server” section in the domain management panel.
- Replace your current Name Servers with the CDN provider’s NS records (e.g.,
ns1.cdnprovider.com,ns2.cdnprovider.com). - Wait for DNS propagation: This may take a few hours to 48 hours for the changes to be visible globally.
- Configure CDN settings: Once the DNS is updated, log in to your CDN provider’s dashboard to fine-tune caching, security settings, and any performance optimizations.
2. CDN with Direct Content Linking (URL-based Routing) | e.g. BlazingCDN
This type of CDN involves delivering content by replacing your media links (images, videos, etc.) with links to the CDN’s domain or a custom domain you configure. This method provides more granular control over what content is served via the CDN.
How it works:
- You receive a unique CDN domain (e.g.,
cdn.yourwebsite.com) or use a pre-configured CDN domain from the provider. - You manually update the URLs for static assets (images, CSS, JavaScript, videos, etc.) on your website to point to this CDN domain.
- Optionally, you can set up a CNAME record to use a custom domain (e.g.,
cdn.yourbrand.com) for better branding.
Advantages:
- Fine-tuned control: You can choose which files or assets are delivered via the CDN.
- No impact on dynamic content: Only static files like images, stylesheets, and scripts are cached, while dynamic content remains unchanged.
- Customization options: You can use your own subdomain (via CNAME) for better integration and branding.
Step-by-step instructions:
Option 1: Using the CDN’s Default Domain
- Sign up with a CDN provider that offers direct content linking (e.g., BlazingCDN, Amazon CloudFront, KeyCDN).
- Get your CDN URL: Once the CDN is set up, the provider will give you a domain (e.g.,
cdn123.cdnprovider.com). - Update content URLs:
- In your website’s HTML or backend system, replace image or file URLs with the CDN link.
- For example, change
<img src="https://yourwebsite.com/images/image1.jpg">to<img src="https://cdn123.cdnprovider.com/images/image1.jpg">.
- Test the new URLs: Ensure the links are working properly and files are being delivered via the CDN.
Option 2: Using a Custom Domain (CNAME Setup)
- Sign up for the CDN service and get the CDN URL (e.g.,
cdn123.cdnprovider.com). - Log in to your domain registrar and navigate to the DNS settings.
- Create a CNAME record:
- Set the Host field as the subdomain you want (e.g.,
cdn.yourwebsite.com). - Set the Value field to point to the CDN domain provided by your CDN provider (e.g.,
cdn123.cdnprovider.com).
- Set the Host field as the subdomain you want (e.g.,
- Wait for DNS propagation: This can take a few hours for global propagation.
- Update content URLs: Replace the URLs of your static files with your custom CDN subdomain (e.g.,
https://cdn.yourwebsite.com/images/image1.jpg). - Test to ensure everything is working properly.
Key Differences Between the Two CDN Types:
| CDN Type | Traffic Proxying (DNS-based) | Direct Content Linking (URL-based) |
|---|---|---|
| Traffic Routing | All traffic is routed through CDN | Only specific assets (images, videos, etc.) are routed |
| DNS Setup | Requires changing Name Servers | Optionally uses a CNAME to map to CDN domain |
| Content Update | No need to update links | Requires updating URLs to point to CDN |
| Control over Content | Entire site is served through CDN | Granular control over which files are served |
| Security & Optimization | Comprehensive security | Limited to static file caching |
By choosing the appropriate CDN type based on your project’s needs, you can significantly improve your website’s speed, reliability, and security.