# NIST SP 800-53 Rev. 5 SA-9(2) — Identification Of Functions, Ports, Protocols, And Services - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-9-2-identification-of-functions-ports-protocols-and-services - Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › SA — System and Services Acquisition - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `SA-9(2)`·high·Component: **System and Services Acquisition** ## What this control requires > Require external service providers to identify the specific functions, ports, protocols, and services necessary for their operation. This supports informed decisions about restricting or blocking components based on risk and operational needs. This control supports the Service Specification Disclosure Protocol capability within the System and Services Acquisition family. > > — NIST SP 800-53 Rev. 5, Control SA-9(2) ### In plain English Require external service providers to identify the specific functions, ports, protocols, and services necessary for their operation. In practice, this means you can prove you security management-level controls on a defined cadence. ## Why it matters SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed. This control is rated **high**. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation. ## What an auditor looks for A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan. Within **System and Services Acquisition**, the assessor will trace your implementation back to the catalogue reference (Control SA-9(2)) and look for objective evidence on the latest two assessment cycles. ## How to implement 1. Write a short policy stating intent, scope and named owner. 2. Encode it as a platform guardrail — SCP, Azure Policy initiative, Organisation Policy, or repository policy. 3. Wire a monitoring signal that catches drift (CSPM rule, SIEM rule, scheduled query, Workspace alert) and ticket it. 4. Review on a documented cadence and capture the review in the risk register or compliance tracker. ### Operational checklist - **Security.** Document the trigger, the owner and the cadence. - **Chain.** Document the trigger, the owner and the cadence. - **System.** Document the trigger, the owner and the cadence. - **Control.** Document the trigger, the owner and the cadence. - **Identify.** Document the trigger, the owner and the cadence. - **Scope:** management, system, service, functions, decisions, components, external service providers, services. ## Evidence to collect - **Vendor Risk Management.** `vendor_risk_management` evidence Third-party risk management evidence (assessments, contracts, due diligence) shows supplier oversight. Focus: Identification Of Functions, Ports, Protocols, And Services. ## How it maps to other frameworks Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit. - [**NIST SP 800-171 Rev. 3 3.16.3** — External System Services](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-16-3-external-system-services) - [**ISO/IEC 27001:2022 A.5.19** — Information security in supplier relationships](https://support.icompaas.com/compliance/iso-27001-2022/a-5-19-information-security-in-supplier-relationships) - [**SOC 2 (2017 TSC) CC9.2** — Vendor Risk Management](https://support.icompaas.com/compliance/soc-2-trust-services-criteria/cc9-2-vendor-risk-management) ## Related controls in NIST SP 800-53 Rev. 5 - [**Control SA-5(2)** — Security-Relevant External System Interfaces](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-5-2-security-relevant-external-system-interfaces) - [**Control SA-12(2)** — Supplier Reviews](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-12-2-supplier-reviews) - [**Control CP-2(7)** — Coordinate With External Service Providers](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/cp-2-7-coordinate-with-external-service-providers) - [**Control SA-13** — Trustworthiness](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-13-trustworthiness) - [**Control SC-7(19)** — Block Communication From Non-Organizationally Configured Hosts](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sc-7-19-block-communication-from-non-organizationally-configured-hosts) - [**Control SA-22** — Unsupported System Components](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/sa-22-unsupported-system-components) ## References - [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls) - Catalogue identifier: `Control SA-9(2)` Topics: vendor riskvendor managementsupply chain securitythird party monitoring ## Related compliance guidance - [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs. - [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement. - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.