Knowledgebase

Overview

This article provides instructions for verifying local DNS caching status and configuring BIND as the local resolver on a Plesk server. Enabling local DNS caching improves query resolution performance and ensures compatibility with services that require recursive DNS functionality.

Prerequisites

• Root or sudo access to the server
• Plesk Obsidian or Plesk Onyx installed
• Network connectivity for package installation and DNS queries

Verify Current DNS Caching Status

Execute the following command to determine whether local DNS caching is currently enabled:

host -tTXT 2.0.0.127.multi.uribl.com

If local DNS caching is disabled, the output will resemble the following:

2.0.0.127.multi.uribl.com descriptive text "127.0.0.1 -> Query Refused. See http://uribl.com/refused.shtml for more information [Your DNS IP: 203.0.113.1]"

Install and Configure BIND as Local Resolver

1. Install the BIND component: If BIND is not already installed, run the following command via Plesk Installer:

   plesk installer add --components bind

2. Validate configuration syntax: Ensure there are no errors in the BIND configuration files by running:

   named-checkconf

   If the command returns no output, the configuration is syntactically correct. Address any reported errors before proceeding.
3. Restart the DNS service: Apply the changes by restarting the appropriate service for your operating system:
   • AlmaLinux/CloudLinux/RHEL:

     systemctl restart named-chroot

   • Debian/Ubuntu:

     systemctl restart bind9

4. Configure the local resolver: Edit the /etc/resolv.conf file and add 127.0.0.1 as the primary nameserver:

   nameserver 127.0.0.1

Verify Configuration

Allow a few minutes for the DNS cache to initialize, then execute the verification command again:

host -tTXT 2.0.0.127.multi.uribl.com

If local DNS caching is successfully enabled, the output will display:

2.0.0.127.multi.uribl.com descriptive text "permanent testpoint"

Troubleshooting & Common Issues

• /etc/resolv.conf overwritten on reboot (RHEL-based systems): If the server uses NetworkManager and DNS entries are defined in /etc/sysconfig/network-scripts/ifcfg-*, the /etc/resolv.conf file will be regenerated upon reboot. To prevent this, either remove the DNS directives from the interface configuration files or use the nmcli utility to configure DNS settings persistently.
• Configuration syntax errors: If named-checkconf returns errors, review the BIND configuration files and correct any malformed directives before restarting the service.
• Delayed cache propagation: DNS caching may require several minutes to populate. If the verification command still returns a refusal message, wait briefly and retry.