DNS (Domain Name System) caching is a process that stores DNS records locally to reduce the time it takes to resolve domain names to IP addresses. However, outdated or incorrect DNS cache entries can lead to browsing issues. This knowledge base provides comprehensive information on DNS cache clearing in WHM cPanel.

Understanding DNS Cache

What is DNS Cache?

DNS cache is a temporary storage of DNS records that helps reduce the time it takes to resolve domain names to their corresponding IP addresses.

Importance of DNS Cache Clearing

1. Correcting Resolution Issues: Clearing DNS cache can resolve issues related to incorrect or outdated DNS records.

2. Testing DNS Changes: After making DNS changes, clearing the cache ensures that the updated records are immediately in effect.

WHM cPanel Tools for DNS Cache Clearing

1. WHM DNS Zone Manager

WHM's DNS Zone Manager allows administrators to manage DNS records for domains hosted on the server.

2. Restarting DNS Server

In WHM, administrators can restart the DNS server to clear its cache and apply any recent changes.

Clearing DNS Cache

Step 1: Log in to WHM

1. Open a web browser and navigate to your WHM login page (usually https://yourdomain.com:2087).

2. Enter your WHM username and password.

Step 2: Accessing DNS Zone Manager

1. In WHM, navigate to Home > DNS Functions > DNS Zone Manager.

2. Select the appropriate domain from the list.

Step 3: Clearing DNS Cache

1. Scroll down to the bottom of the page, and click on Delete next to the 'Record Statistics' section.

2. A confirmation pop-up will appear; click Yes to proceed.

Common DNS Cache Issues and Solutions

1. Outdated Cache Entries

• Cause: Cached DNS records may become outdated, leading to resolution problems.

• Solution: Clear the DNS cache to force the system to fetch updated records.

2. Incorrect DNS Records

• Cause: Incorrect or misconfigured DNS records can lead to resolution failures.

• Solution: Review and correct DNS records in WHM's DNS Zone Manager.

3. Propagation Delays

• Cause: Changes in DNS records can take time to propagate across the internet.

• Solution: Be patient, as it may take some time for DNS changes to take effect.

Troubleshooting DNS Cache Issues

1. Flush Client-Side DNS Cache

1. Open a command prompt or terminal window.

2. Type the command to flush the DNS cache:

   • For Windows: ipconfig /flushdns

   • For macOS and Linux: sudo dscacheutil -flushcache

2. Verify DNS Records

1. Use online DNS lookup tools to verify that the correct DNS records are in place.

2. Cross-check with the records in WHM's DNS Zone Manager.

3. Check TTL Values

1. Review the TTL (Time To Live) values in the DNS records to ensure they are appropriately configured.

2. Lower TTL values can expedite DNS propagation.

Best Practices for DNS Cache Clearing

1. Monitor DNS Changes: Keep track of any changes made to DNS records to ensure they propagate correctly.

2. Clear Browser Cache: In addition to clearing server-side DNS caches, advise users to clear their browser cache if they encounter resolution issues.

3. Implement Proper TTLs: Set appropriate TTL values in DNS records to balance caching efficiency with the need for rapid updates.

Conclusion

Clearing DNS cache is a critical troubleshooting step for resolving domain name resolution issues. By following the guidelines provided in this knowledge base, you can efficiently clear DNS cache in WHM cPanel. Regular cache clearing and best practices will help ensure smooth and accurate DNS resolution on your server.