Troubleshooting

Diagnose and fix common issues with CDN, WAF, DNS configuration, and visitor IP restoration.

WAF/CDN Connection Errors

Troubleshoot common 502, 503, and 504 errors when traffic passes through the NOC WAF and CDN. Includes origin connectivity checks.

Troubleshooting DNS with dig

Use the dig command to verify DNS propagation, check authoritative responses, and debug resolution issues with your NOC-hosted domains.

Restore Visitor IP

When traffic flows through the NOC CDN or WAF, your origin sees NOC edge IPs. Learn how to restore the real visitor IP in Apache, Nginx, and application logs.

MySQL ERROR 1064

Fix SQL syntax errors caused by shell escaping when passing CREATE USER and other statements via SSH.

MySQL ERROR 1819 — Password Policy

Resolve password validation errors by understanding MySQL's validate_password policy levels.

Set MySQL Root Password

Set or reset the MySQL root password when it's empty or using auth_socket authentication.

SSL Certificate Migration Errors

Fix certificate chain, key mismatch, and permission errors when moving SSL certs between servers.

Recovering Deleted Files on Linux

Use extundelete, testdisk, and /proc recovery to restore accidentally deleted files on ext3/ext4.

Apache MultiViews Issues

Troubleshoot content negotiation problems caused by Apache's MultiViews option.

PHP-FPM Pool Setup

Fix WordPress asking for FTP credentials by correcting PHP-FPM pool user/group ownership.

PHP-FPM Listen Address Error

Resolve duplicate socket conflicts when multiple PHP-FPM pools share the same listen address.

Apache VirtualHosts on Ubuntu

Configure VirtualHosts for multiple sites on one Apache server with SSL support.

Remove index.php from WordPress URLs

Fix WordPress permalink issues by enabling mod_rewrite and configuring .htaccess.

WordPress Memory Exhausted

Increase PHP memory limits in wp-config.php and php.ini to resolve memory exhausted errors.

WordPress Missing MySQL Extension

Install the correct PHP MySQL extension for your PHP version to fix the missing extension error.