Troubleshooting issues involving a Web Application Firewall (WAF), Content Delivery Network (CDN), and Load Balancer (LB) can be complex. Here is a step-by-step guide, including testing methods and relevant commands to isolate problems at each level. ### Step 1: Check Basic Connectivity 1. **Ping the Website**: ```sh ping example.com ``` 2. **Check DNS Resolution**: ```sh nslookup example.com ``` ### Step 2: Verify Load Balancer 1. **Direct Access to Load Balancer**: Modify `/etc/hosts` to bypass CDN and WAF, pointing directly to the load balancer’s IP. ```sh sudo nano /etc/hosts ``` Add the line: ``` LB_IP example.com ``` 2. **Test HTTP Response**: ```sh curl -I http://example.com ``` Check headers and status code to verify the load balancer is responding correctly. 3. **Check Load Balancer Logs**: Access logs on the load balancer to see if requests are hitting it and how they are being routed. ```sh tail -f /var/log/
SA Bagus is a blog about computer technology, networking, cloud, crypto, and cyber security.