How to Check DNSSEC for a Domain

1. Online: Enterno DNS Checker → enter domain → DNSSEC section shows DNSKEY + DS + validation status
2. Via dig: dig +dnssec +short example.com DNSKEY for keys; dig +dnssec example.com DS for DS records
3. Full chain: dig +dnssec +trace example.com — trace from root
4. delv (validation-focused): delv @8.8.8.8 example.com — "fully validated" = OK
5. External analyzer: Verisign DNSSEC Analyzer — shows every chain issue
6. Browser extension: DNSSEC/TLSA Validator (Firefox, Chrome) — address-bar icon

• Default resolvers (routers, Windows) often do NOT validate — use 1.1.1.1, 8.8.8.8, 9.9.9.9
• dig +dnssec shows records but does not validate — use delv or +trace
• Broken DNSSEC = SERVFAIL for 25-40% of validating clients — domain becomes "down"
• The DS record in the TLD is published by the registrar. Rotating keys without updating DS → every client gets SERVFAIL

To check DNSSEC for a domain, use the dig command-line tool with the +dnssec flag followed by the domain name. For example, dig +dnssec example.com will return DNSSEC-related records. Verify the presence of RRSIG and DNSKEY records to confirm DNSSEC is enabled. If you're in the EU, ensure compliance with GDPR when handling DNS data.

Domain Name System Security Extensions (DNSSEC) is a suite of extensions that add a layer of security to the DNS protocol. It ensures that the responses to DNS queries are authentic and have not been tampered with during transit. DNSSEC uses public key cryptography to sign DNS data, allowing resolvers to verify the authenticity of the data they receive.

In the context of DNSSEC, there are several key components:

• Zone Signing Key (ZSK): This key is used to sign the zone's DNS records.
• Key Signing Key (KSK): This key is used to sign the ZSK and is stored in the parent zone.
• Resource Records: These include RRSIG (signature records), DNSKEY (key records), and DS (Delegation Signer) records.

When a resolver queries a DNSSEC-enabled zone, it receives both the DNS records and the corresponding RRSIG records. The resolver can then use the DNSKEY records to verify the RRSIG signatures, ensuring the integrity of the data.

To check if DNSSEC is enabled for a specific domain, follow these practical steps using the dig command-line tool:

1. Open your terminal: Ensure you have access to a terminal or command prompt.
2. Run the dig command: Execute the following command to query the DNSSEC information:

dig +dnssec example.com

Replace example.com with your domain name. The output will include several sections, but you should focus on the ANSWER SECTION and ADDITIONAL SECTION.

In the ANSWER SECTION, look for:

• RRSIG: This indicates that the records are signed. Verify the validity of the signature by checking its expiration date.
• DNSKEY: This record contains the public key used to verify the RRSIG signatures.

In the ADDITIONAL SECTION, you may find the DNSKEY record. If both RRSIG and DNSKEY records are present, DNSSEC is enabled for the domain.

For further verification, you can also check the DS records in the parent zone:

dig DS example.com

If a DS record is returned, it indicates that the parent zone knows about the DNSKEY, thus confirming DNSSEC is properly configured. For example, a DS record may look like:

example.com. 86400 IN DS 12345 8 2 3A2B...1234

In this case, the values represent the key tag, algorithm, and digest type, respectively. Ensure that the values align with the DNSKEY records to maintain a secure chain of trust.