id: "SC-22" title: "Architecture and Provisioning for Name/Address Resolution Service" family: "SC" family_name: "System and Communications Protection" sort_id: "sc-22" priority: "P1" implementation_level: "system"
Statement
Ensure the systems that collectively provide name/address resolution service for an organization are fault-tolerant and implement internal and external role separation.
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).
Assessment Objective: the systems that collectively provide name/address resolution services for an organization are fault-tolerant;
Assessment Objective: the systems that collectively provide name/address resolution services for an organization implement internal role separation;
Assessment Objective: the systems that collectively provide name/address resolution services for an organization implement external role separation.
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
System/network administrators
organizational personnel with information security responsibilities
organizational personnel with responsibilities for managing DNS
Mechanisms supporting and/or implementing name/address resolution services for fault tolerance and role separation