Architecture and Provisioning for Name/Address Resolution Service
✓ LOW ✓ MODERATE ✓ HIGHRequirements NIST SOURCE
Ensure the systems that collectively provide name/address resolution service for an organization are fault-tolerant and implement internal and external role separation.
Discussion (NIST Supplemental Guidance)
Systems that provide name and address resolution services include domain name system (DNS) servers. To eliminate single points of failure in systems and enhance redundancy, organizations employ at least two authoritative domain name system servers—one configured as the primary server and the other configured as the secondary server. Additionally, organizations typically deploy the servers in two geographically separated network subnetworks (i.e., not located in the same physical facility). For role separation, DNS servers with internal roles only process name and address resolution requests from within organizations (i.e., from internal clients). DNS servers with external roles only process name and address resolution information requests from clients external to organizations (i.e., on external networks, including the Internet). Organizations specify clients that can access authoritative DNS servers in certain roles (e.g., by address ranges and explicit lists).
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for SC-22 yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.
Assessment
Assessment Objectives
- the systems that collectively provide name/address resolution services for an organization are fault-tolerant;
- the systems that collectively provide name/address resolution services for an organization implement internal role separation;
- the systems that collectively provide name/address resolution services for an organization implement external role separation.
Examine
[SELECT FROM: System and communications protection policy; procedures addressing architecture and provisioning for name/address resolution services; access control policy and procedures; system design documentation; assessment results from independent testing organizations; system configuration settings and associated documentation; system audit records; system security plan; other relevant documents or records].
Interview
[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities; organizational personnel with responsibilities for managing DNS].
Test
[SELECT FROM: Mechanisms supporting and/or implementing name/address resolution services for fault tolerance and role separation].
Overlays
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for SC-22. This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.
Learn more about STIG/CCI integration →Evidence
Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.
Policy
- System and communications protection policy
- access control policy and procedures
- system security plan
Configuration
- procedures addressing architecture and provisioning for name/address resolution services
- system design documentation
- system configuration settings and associated documentation
Testing
- Mechanisms supporting and/or implementing name/address resolution services for fault tolerance and role separation
Other Records
- assessment results from independent testing organizations
- system audit records
- other relevant documents or records