SC-21 — Secure Name/Address Resolution Service (Recursive or Caching Resolver)
Each client of name resolution services either performs this validation on its own or has authenticated channels to trusted validation providers. Systems that provide name and address resolution services for local clients include recursive resolving or caching domain name system (DNS) servers. DNS client resolvers either perform validation of DNSSEC signatures, or clients use authenticated channels to recursive resolvers that perform such validations. Systems that use technologies other than the DNS to map between host and service names and network addresses provide some other means to enable clients to verify the authenticity and integrity of response data.
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NIST CSF 2.0 informative references
These CSF Subcategories list this base control or one of its enhancements in the imported NIST informative reference.
NIST SP 800-171 and SP 800-172
SP 800-171 requirements sourcing this control
SP 800-172 enhanced requirements sourcing this control
MITRE D3FEND techniques
MITRE ATT&CK relationships
Curated mitigation mappings
Inferred behavior relationships
Experimental: These relationships are inferred through D3FEND and must be validated against architecture, telemetry, and threat context.
Use the map without overclaiming.
A CSF informative reference is not an equivalence statement. A source-control relationship is not proof of implementation. A D3FEND semantic relationship is not a product claim. An inferred ATT&CK link is a hypothesis for engineering analysis.
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST or MITRE. Informative references and cross-framework relationships support navigation and analysis; they do not establish compliance, applicability, equivalence, control inheritance, or guaranteed mitigation effectiveness.