Sites are unavailable: nginx: [emerg] bind() to failed (99: Cannot assign requested address)

Symptoms

• Domains are not available with:

  CONFIG_TEXT: 500 internal server error

• Default Plesk page is shown instead of the domain's content

• The following error is shown in Plesk:

  PLESK_ERROR: New configuration files for the Apache web server were not created due to the errors in configuration templates: nginx: [emerg] bind() to 203.0.113.2:80 failed (99: Cannot assign requested address) nginx: configuration file /etc/nginx/nginx.conf test failed . Detailed error descriptions were sent to you by email. Please resolve the issues and click here to generate broken configuration files once again or here to generate all configuration files. See the details in Configuration Troubleshooter

• A similar error can be seen when starting Nginx via SSH:

  # service nginx start
  nginx: [emerg] bind() to 203.0.113.2:80 failed (99: Cannot assign requested address)

• Apache is listening on 80 (443) port:

  # netstat -tlpn | grep :80
  tcp6 0 0 :::80 :::* LISTEN 15726/httpd

• Nginx is enabled:

  # plesk sbin nginxmng -s
  Enabled

Cause

Web server misconfiguration: nginx is enabled, but it does not listen to 80/443 ports for http/https connections.

Resolution

1. Connect to the server using SSH.

2. Re-enable nginx so that nginx and apache are re-configured on correct ports:

   # plesk sbin nginxmng -d
   # plesk sbin nginxmng -e