Analyzing and Resolving DNSSEC Problems: A Comprehensive Guide Print

Introduction

DNSSEC (Domain Name System Security Extensions) adds an additional layer of security to the DNS protocol by enabling DNS responses to be authenticated. While DNSSEC provides significant security benefits, improper configuration can lead to domain resolution issues. This article discusses how to analyze DNSSEC problems, use diagnostic commands, and troubleshoot DNSSEC issues. Additionally, it provides guidance on how to remove DNSSEC records if they are not required.

Understanding DNSSEC

DNSSEC ensures that the responses to DNS queries are authentic by using digital signatures. This helps protect against certain types of attacks, such as cache poisoning and spoofing. However, for DNSSEC to function correctly, it requires proper configuration of DNSKEY, DS, and RRSIG records.

Analyzing DNSSEC Problems

Common DNSSEC Issues

1. Missing DNSKEY Records: The domain lacks the necessary DNSKEY records at the hosting provider.
2. Mismatched DS Records: DS records at the domain registrar do not match the DNSKEY records.
3. Incomplete DNSSEC Setup: DNSSEC enabled at the domain registrar but not at the hosting provider, or vice versa.

Diagnostic Commands for DNSSEC

Using dig to Verify DNSSEC Records

• Check DNSKEY Records :

dig example.com DNSKEY +dnssec
- Check DS Records:

dig example.com DS +dnssec

- Check RRSIG Records:

dig example.com A +dnssec

Online Tools for DNSSEC Diagnosis

1. Verisign DNSSEC Analyzer:

   • Visit Verisign DNSSEC Analyzer.
   • Enter example.com and run the analysis to check for DNSSEC issues.

2. DNSViz:

   • Visit DNSViz.
   • Enter your domain and run a diagnostic check to visualize and identify DNSSEC configuration problems.

Why the Domain Works on Some Internet Connections but Not Others

When DNSSEC is improperly configured, it can cause your domain to resolve correctly on some internet connections while failing on others. This inconsistency is due to how different DNS resolvers handle DNSSEC validation:

1. Strict DNSSEC Validation:

   • Some DNS resolvers, especially those used by ISPs or enterprise networks, enforce strict DNSSEC validation. If they detect mismatched or missing DNSSEC records, they will not resolve the domain. This results in users on these networks being unable to access the domain.

2. Lenient DNSSEC Validation:

   • Other DNS resolvers may be configured to bypass DNSSEC validation errors. These resolvers will attempt to resolve the domain even if there are issues with DNSSEC records. As a result, users on these networks might still be able to access the domain.

3. Cached DNS Records:

   • DNS resolvers that have previously cached the correct DNS records for the domain might continue to serve those cached records until they expire. This can cause the domain to be accessible for some users until the cached records are refreshed and the DNSSEC validation issue is encountered.

Example Scenario

Imagine you have DNSSEC enabled for a domain, but the DNSKEY records are missing from your hosting provider's DNS settings. Here's what might happen:

• User A (Strict Validation):

  • User A's ISP uses a DNS resolver that strictly enforces DNSSEC validation. When User A tries to access the domain, the resolver checks the DNSSEC records and finds that the necessary DNSKEY records are missing. Consequently, the resolver fails to resolve the domain, and User A cannot access the website.

• User B (Lenient Validation):

  • User B's ISP uses a DNS resolver that does not strictly enforce DNSSEC validation. When User B tries to access the domain, the resolver bypasses the DNSSEC validation errors and resolves the domain using the available DNS records. Therefore, User B can access the website without issues.

Resolving DNSSEC Issues

Step 1: Verify DNSSEC Records at Domain Registrar

1. Log in to your domain registrar’s control panel.
2. Navigate to the DNSSEC settings for your domain.
3. Verify the existing DS records.

Step 2: Configure DNSSEC on Your Hosting Provider

1. Log in to your hosting provider’s control panel.
2. Navigate to the DNS settings for your domain.
3. Enable DNSSEC and generate the necessary DNSKEY and RRSIG records.

Step 3: Update DS Records at Registrar

1. Copy the DNSKEY information from your hosting provider.
2. Log back into your domain registrar’s control panel.
3. Update the DS records to match the DNSKEY information from your hosting provider.

Removing DNSSEC Records if Not Required

If DNSSEC is not required or if it was not set up by you, removing the DNSSEC records can resolve the resolution issues.

Steps to Remove DNSSEC Records

1. At the Domain Registrar:

   • Log in to your domain registrar’s control panel.
   • Navigate to the DNSSEC settings for your domain.
   • Remove the DS records.

2. At the Hosting Provider:

   • Log in to your hosting provider’s control panel.
   • Navigate to the DNS settings.
   • Disable DNSSEC and remove DNSKEY and RRSIG records.

Additional Resources

For detailed guides on setting up and managing DNSSEC, refer to the following resources:

• How to Enable and Set Up DNSSEC in cPanel
• Implementing DNSSEC on DomainIndia.com

Conclusion

Properly configuring DNSSEC is essential for securing your domain, but misconfiguration can lead to resolution issues. By analyzing DNSSEC problems, using diagnostic commands, and following the correct steps for setup or removal, you can ensure that your domain remains accessible and secure. If DNSSEC is not needed, removing the DNSSEC records can prevent unnecessary complications.