SC-48: Sensor Relocation

SC-48 requires you to predefine when and how you will move security sensors (for example, IDS/IPS, network taps, EDR collectors, OT sensors, application sensors) from one location to another, then execute those moves under controlled conditions with documented approvals and validation. Operationalize it by defining sensor types, approved destination zones, trigger conditions, and post-move verification evidence. ¹

Key takeaways:

• Treat sensor relocation as a controlled change that must preserve detection coverage and evidence integrity.
• Define “what sensors,” “from where to where,” and “under what conditions” in writing, then follow that playbook every time.
• Keep relocation tickets, diagrams, approvals, and post-move validation results as primary audit evidence.

SC-48: Sensor Relocation is a small control with outsized operational impact because it touches both security monitoring coverage and the integrity of your detection program. If your sensors move informally during network redesigns, cloud migrations, data center exits, or third-party managed service transitions, you can create blind spots exactly when risk is highest: during change.

NIST’s text is intentionally parameterized, which means you must decide and document the specifics for your environment: which sensors are in scope, the approved “to” locations, and the exact conditions that trigger a relocation. Your assessor will then test whether you followed your own defined conditions and whether monitoring coverage remained effective after the move. ¹

This page translates the sc-48: sensor relocation requirement into an operator-ready procedure. It focuses on what a Compliance Officer, CCO, or GRC lead needs to do to assign ownership, force the right approvals, ensure engineering validates coverage, and retain defensible evidence for audits and customer security reviews.

Regulatory text

Requirement (verbatim excerpt): “Relocate {{ insert: param, sc-48_odp.01 }} to {{ insert: param, sc-48_odp.02 }} under the following conditions or circumstances: {{ insert: param, sc-48_odp.03 }}.” ¹

What the operator must do with this text

Because SC-48 is written with organization-defined parameters, your job is to:

1. Name what must be relocated (the sensor classes and, if needed, specific deployments).
2. Define the allowed destination(s) (networks, enclaves, accounts, segments, facilities, or security zones).
3. Define the triggering conditions (the circumstances that require relocation, and the change-control gates that must be met before a move).

Then you must execute relocations consistently with those definitions and retain evidence that the move occurred under the right conditions and did not degrade monitoring. ¹

Plain-English interpretation (what SC-48 is really asking)

You must be able to answer, with documentation and tickets:

• “When our environment changes, how do we ensure the sensors that provide detection and visibility move with it?”
• “Who authorizes a sensor move, and how do we validate coverage after the move?”
• “How do we prevent blind spots created by ad hoc network changes, cloud re-architecture, or third-party transitions?”

SC-48 is not a “buy a tool” requirement. It is a repeatable operational control that ties security architecture (where sensors sit) to change management (when they move) and monitoring assurance (how you prove they still work).

Who it applies to

SC-48 is commonly expected in:

• Federal information systems and programs aligned to NIST SP 800-53. ²
• Contractor systems handling federal data, including environments operated by third parties (for example, managed hosting, MSP/SOC, SaaS dependencies), where sensor placement affects federal data monitoring. ²

Operational contexts where SC-48 shows up in real assessments:

• Network segmentation projects (new DMZs, new enclaves, zero trust segmentation)
• Cloud migrations (moving workloads from on-prem to IaaS/PaaS)
• Data center consolidation or exit
• SOC tool changes (new IDS, new logging pipeline, new EDR back end)
• M&A integration where monitoring stacks are merged
• OT/IoT deployments where physical sensors are moved or re-homed

What you actually need to do (step-by-step)

Step 1: Define the SC-48 parameters for your environment

Create a short “SC-48 Parameter Sheet” (one page is fine) that fills in the blanks:

• In-scope sensors (ODP.01): e.g., network IDS/IPS sensors, network taps, NDR sensors, EDR collectors, WAF/app sensors, OT sensors, cloud traffic mirroring sensors, critical log forwarders that act as “sensors.”
• Approved destinations (ODP.02): e.g., specific network security zones, cloud accounts/subscriptions, VPC/VNet segments, facilities, or “security monitoring enclaves.”
• Triggering conditions (ODP.03): use concrete triggers:
  • introduction of a new network segment hosting regulated/federal-data workloads
  • decommissioning or isolation of a segment where sensors currently reside
  • changes to routing, NAT, or traffic inspection points
  • third party takes over hosting/operations and sensor handoff is required
  • incident response containment steps that require temporarily moving sensors

Your assessor will treat these as your “law” for SC-48. Write them so engineering can execute without interpretation disputes. ¹

Step 2: Assign ownership and approval authority

Set explicit roles:

• Control owner (GRC): maintains the parameter sheet, audit evidence, and mapping to change management.
• Technical owner (Security Architecture/SOC Engineering): designs sensor placement, approves destination validity, sets validation tests.
• Change authority (CAB/Change Manager): enforces that relocations cannot happen outside change control except under defined emergency criteria.

If a third party runs monitoring, name them and define the interface: who opens tickets, who approves moves, and who provides post-move evidence.

Step 3: Build “sensor relocation” into your change-management workflow

Add a required question (or change template) for relevant changes:

• “Does this change add/remove/alter a network boundary, traffic path, or monitored asset group?”
• If yes, “Does it require sensor relocation per SC-48 parameter sheet?”

Require that the change record includes:

• current sensor location
• proposed sensor location
• coverage impact assessment (expected blind spots during cutover)
• back-out plan
• validation plan and success criteria

Step 4: Maintain a living sensor inventory and placement map

You need an inventory that ties sensors to:

• unique sensor ID / hostname / agent group
• monitored assets or traffic path
• current placement (network segment, cloud account, facility)
• tool owner and data destination (SIEM, data lake, SOC platform)

Pair it with diagrams:

• network/security zone diagram showing sensor points
• cloud reference architectures showing mirroring/logging points

This is your fastest way to prove SC-48 is engineered, not improvised.

Step 5: Execute relocation with controlled cutover and verification

For each relocation:

1. Pre-move checkpoint: confirm baselines (sensor health, event rates, data delivery).
2. Move execution: perform change under approved window or emergency procedure defined in your SC-48 conditions.
3. Post-move validation: verify:
   • sensor is receiving expected traffic/telemetry
   • telemetry reaches the monitoring backend
   • detections/alerts still fire (use test events where feasible)
4. Coverage confirmation: confirm no critical assets lost monitoring due to path changes, routing asymmetry, or encryption shifts.
5. Closeout: attach evidence and update inventory and diagrams.

Step 6: Make it assessable: map SC-48 to procedure + recurring evidence

A recurring failure mode is “we do this, but we can’t prove it.” Your minimum bar is a documented procedure and a predictable evidence set. Daydream (or your GRC system) should track SC-48 to an owner, a procedure, and a recurring evidence cadence so you can answer audits quickly with consistent artifacts. ¹

Required evidence and artifacts to retain

Keep evidence that shows both control design (your rules) and control operation (you followed them):

Design artifacts

• SC-48 Parameter Sheet (ODP.01, ODP.02, ODP.03 filled in)
• Sensor relocation SOP / runbook
• RACI for approvals (GRC, Security Architecture, SOC Engineering, CAB)
• Sensor inventory standard (fields required, system of record)
• Network/security zone diagrams and cloud architecture diagrams showing sensor points

Operational artifacts ¹

• Change ticket(s) with approvals and implementation notes
• Pre/post sensor health checks (screenshots or exported reports)
• Post-move validation results (test alerts, log receipt confirmations)
• Updated inventory record and updated diagram revision
• If emergency move: documented justification aligned to your defined SC-48 conditions

Common exam/audit questions and hangups

Auditors usually probe four areas:

1. “What are your organization-defined parameters for SC-48?”
   Hangup: you can’t point to a single place where ODPs are defined. Fix: one-page parameter sheet plus SOP. ¹

2. “Show me a relocation and prove monitoring was preserved.”
   Hangup: tickets lack validation evidence. Fix: require post-change validation attachments.

3. “How do you know sensors didn’t drift over time?”
   Hangup: inventory and diagrams are stale. Fix: make inventory update a closure criterion for relevant changes.

4. “What about third parties that host parts of the system?”
   Hangup: you rely on an MSP/SOC but have no defined handoff evidence. Fix: contractually require relocation evidence packages and access to health/status reports.

Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails in practice	Avoid it by doing this
Treating SC-48 as “network team handles it”	Monitoring coverage is a security assurance obligation, not a pure network task	Put CAB gating and security approval into the workflow
Defining ODPs too vaguely (“move sensors as needed”)	Assessors can’t test it; engineers can’t execute consistently	Write concrete triggers and allowed destination zones 1
No post-move verification	You can relocate and silently lose telemetry	Require health checks + test detections as closure criteria
Ignoring cloud-native “sensor equivalents”	Traffic mirroring/logging points move during refactors	Include cloud sensors and log pipeline components in ODP.01
Letting diagrams/inventory rot	You can’t prove placement or coverage	Make updates mandatory and version-controlled

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for SC-48, so you should treat it as an assurance and auditability requirement rather than a penalty-driven one.

Operational risk is still real:

• Detection blind spots during change: relocation is most common during migrations and redesigns, which are also high-risk periods.
• Evidence gaps: inability to demonstrate where sensors were and why they moved can drive audit findings, customer escalations, and authorization delays in federal programs.

A practical 30/60/90-day execution plan

Use phases rather than date promises. The goal is to become assessable quickly, then mature.

First 30 days (foundation and scoping)

• Assign SC-48 control owner and technical owners.
• Draft the SC-48 Parameter Sheet (ODP.01/02/03) and get it approved by Security Architecture and CAB. ¹
• Identify systems and segments that handle federal data (or other in-scope data) and list the sensors tied to them.
• Update change templates to include the SC-48 relocation trigger questions.

Days 31–60 (process integration and evidence standardization)

• Publish the sensor relocation SOP/runbook with step-by-step validation requirements.
• Stand up or clean up the sensor inventory (system of record) and define required fields.
• Create evidence checklists for relocation tickets (what screenshots/reports must be attached).
• Run one tabletop for a “network redesign” change and one for an “emergency relocation” scenario tied to your defined SC-48 conditions.

Days 61–90 (operate and prove)

• Execute the SOP on real changes and collect evidence packages.
• Review tickets for completeness; fix template gaps.
• Add an internal control check: periodic review of sensor inventory vs. actual tool telemetry sources (SOC engineering can reconcile).
• In Daydream (or your GRC platform), map SC-48 to owner, procedure link, and the recurring evidence artifacts so audit requests can be fulfilled without rework. ¹

Frequently Asked Questions

What counts as a “sensor” for SC-48?

Treat any component that provides security monitoring telemetry as a sensor, including network IDS/IPS, NDR, OT sensors, and critical log collection points when they function as detection sources. Define your in-scope list explicitly in the SC-48 parameters. ¹

Does SC-48 require moving sensors every time the network changes?

It requires you to relocate sensors under the conditions you define. If your condition set is “any change that alters traffic paths for in-scope workloads,” then yes, it becomes frequent; if you narrow conditions, document the rationale and ensure coverage remains acceptable. ¹

How do we handle sensor relocation in cloud environments where there’s no “physical” sensor?

Model cloud-native telemetry points as relocatable: VPC/VNet traffic mirroring targets, flow log collection points, WAF/app sensor placement, and log forwarding routes. Your evidence should show the before/after configuration and confirmation of log/alert receipt.

What evidence is strongest for audits?

A change ticket with approvals, before/after diagrams or config exports, and post-move validation results (sensor health plus proof telemetry reached the monitoring backend). Also retain the parameter sheet that defines your triggers and allowed destinations. ¹

We outsource monitoring to a third party SOC. Can they “own” SC-48?

They can operate parts of it, but you still need internal accountability for defining the conditions, approving relocations, and retaining evidence. Add contractual requirements for relocation evidence packages and clearly define who updates inventories and diagrams.

What’s the fastest way to fail SC-48 in an assessment?

Having no written organization-defined parameters and no consistent evidence that relocations were approved and validated. If you can’t show a completed relocation package end-to-end, expect a finding. ¹

Footnotes

1. NIST SP 800-53 Rev. 5 OSCAL JSON

2. NIST SP 800-53 Rev. 5