Step-by-Step Guide to Manually Editing DNS Zone Files Safely Make it Rain Paper

Pre-requisites:

• Basic understanding of DNS and zone files.
• Access to the server with necessary permissions to edit DNS settings.
• Familiarity with command-line text editors (e.g., nano, vim).

Editing DNS zone files is a critical task that requires precision. If not done correctly, changes may not take effect. Follow this guide to ensure safe and effective manual edits to your DNS zone files.

Procedure for Editing DNS Zone Files

1. Backup Existing Zone Files

Before making any changes, create a backup of the DNS zones you plan to edit. To back up all zones, use the following command:

cp -av /var/named /var/named-backup

2. Open the Zone File

Using your preferred command-line text editor, open the specific zone file. Zone files are located in /var/named and have a .db extension.

3. Update the Serial Number

After making your desired changes, you must update the serial number in the zone file. Increasing the serial number indicates that changes have been made. For example:

2023061802 ; Serial Number

Simply increment the number by one digit.

4. Check Zone Syntax

Verify the syntax of the zone file using named-checkzone. If it returns "OK," you can proceed to reload the zone. If there are errors, address them before continuing. Use the following command format:

named-checkzone example.tld /var/named/example.tld.db

Example output:

zone example.tld/IN: loaded serial 2023062201
OK

5. Reload the DNS Zone

After updating the serial number, reload the zone. The command will vary depending on the nameserver:

• PowerDNS:

pdns_control bind-reload-now example.tld

• BIND:

rndc reload

6. Sync DNS Cluster (if applicable)

If you are using a DNS cluster with cPanel, initiate a sync for the modified zone using the following command:

/scripts/dnscluster synczone example.tld

Manual edits to DNS zone files can significantly impact your domain's functionality. By following this multi-step procedure and ensuring that all changes are properly validated, you can avoid common pitfalls and maintain a reliable DNS configuration.