What should you ensure is served to validate DNSSEC configurations?

To validate DNSSEC configurations, it is essential to ensure that a DS (Delegation Signer) record is served. A DS record is used specifically in the DNSSEC architecture to establish a trust chain between a parent zone and a child zone. This record contains a hash of the child zone's DNSKEY record, allowing resolvers to verify that the child zone's DNS data is authentic and has not been tampered with.

When a DNS resolver queries a zone that is DNSSEC-secured, it checks for the presence of the DS record in the parent zone. If the DS record is present, the resolver can then validate the signatures of the DNSKEY and other records from the child zone, thereby ensuring the authenticity of the DNS responses.

In contrast, other record types such as A, CNAME, and MX records serve different purposes in DNS. An A record points to an IP address for a domain, a CNAME record redirects one domain to another, and MX records are used to specify mail exchange servers for email routing. While these records could exist in a DNSSEC-enabled zone, they do not play a direct role in establishing the security context and trust required to validate DNSSEC configurations.