Government Cloud Architecture

FedRAMP High and Impact Level 4-5 compliant architecture for government workloads.

Table of Contents

1. Table of Contents
2. Overview
3. Learning Objectives
4. Government Cloud Architecture
5. FedRAMP Control Families
   1. NIST 800-53 Implementation
   2. FedRAMP High Baseline
6. Impact Level Segmentation
   1. IL4 Workload Zone
   2. IL5 Workload Zone
7. Connectivity Patterns
   1. ExpressRoute Government
   2. Network Segmentation
8. CAC/PIV Authentication
   1. Entra ID Configuration
   2. Conditional Access Policy
9. Continuous Monitoring
   1. FISMA Reporting
   2. Automated POA&M Generation
10. Implementation Checklist
11. Next Steps

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Overview

Government organizations require the highest levels of security and compliance. This architecture covers deployments in Azure Government regions with FedRAMP High authorization and support for Impact Level 4 (IL4) and IL5 workloads, including Controlled Unclassified Information (CUI) and National Security Systems.

Learning Objectives

After completing this section, you will be able to:

• ✅ Design FedRAMP High compliant architectures
• ✅ Implement IL4/IL5 workload isolation
• ✅ Configure compliant connectivity patterns
• ✅ Meet NIST 800-53 control requirements

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Government Cloud Architecture

Region	Location	IL Support	Services
US Gov Virginia	Virginia, USA	IL2, IL4, IL5	Full
US Gov Texas	Texas, USA	IL2, IL4, IL5	Full
US Gov Arizona	Arizona, USA	IL2, IL4, IL5	Full
US DoD Central	Iowa, USA	IL5, IL6	DoD only
US DoD East	Virginia, USA	IL5, IL6	DoD only

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FedRAMP Control Families

NIST 800-53 Implementation

Control Family	Azure Implementation
AC - Access Control	Entra ID, RBAC, PIM
AU - Audit	Log Analytics, Sentinel
CA - Assessment	Defender for Cloud
CM - Configuration	Azure Policy, Blueprints
CP - Contingency	Backup, Site Recovery
IA - Identification	Entra ID, MFA, CAC/PIV
IR - Incident Response	Sentinel, Playbooks
SC - System Protection	NSG, Firewall, Encryption
SI - System Integrity	Defender, Update Management

FedRAMP High Baseline

# Azure Policy initiative for FedRAMP High
policyAssignment:
  name: "FedRAMP-High-Baseline"
  scope: "/subscriptions/{gov-subscription}"
  policyDefinitionId: "/providers/Microsoft.Authorization/policySetDefinitions/d5264498-16f4-418a-b659-fa7ef418175f"
  parameters:
    logAnalyticsWorkspaceId: "/subscriptions/{sub}/resourceGroups/mgmt-rg/providers/Microsoft.OperationalInsights/workspaces/gov-logs"

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Impact Level Segmentation

IL4 Workload Zone

For Controlled Unclassified Information (CUI):

Requirement	Implementation
Data Encryption	TDE + CMK (FIPS 140-2)
Access Control	CAC/PIV + MFA
Network	Dedicated VNet, ExpressRoute
Monitoring	FedRAMP audit logging

IL5 Workload Zone

For National Security Systems and higher-sensitivity CUI:

Requirement	Implementation
Complete Isolation	Dedicated VNet, no peering
HSM Keys	Dedicated HSM (FIPS 140-2 L3)
Access Control	CAC/PIV + location-based
Internet	Blocked (air-gap capable)
Personnel	US Persons only

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Connectivity Patterns

ExpressRoute Government

# Configure ExpressRoute for Government
New-AzExpressRouteCircuit `
    -Name "gov-expressroute" `
    -ResourceGroupName "connectivity-rg" `
    -Location "usgovvirginia" `
    -SkuTier "Premium" `
    -SkuFamily "MeteredData" `
    -ServiceProviderName "AT&T Netbond" `
    -PeeringLocation "Washington DC" `
    -BandwidthInMbps 1000

Network Segmentation

graph TB
    subgraph GovDC ["Government Data Center"]
        A[Agency Network]
        B[Classified Network]
    end

    subgraph Azure ["Azure Government"]
        C[ExpressRoute Gateway]
        D[Hub VNet]
        E[IL4 VNet]
        F[IL5 VNet]
    end

    A -->|ExpressRoute| C
    B -.->|❌ No Connection| F
    C --> D
    D -->|Peering| E
    D -.->|Isolated| F

    style B fill:#FFE4E1,stroke:#D13438
    style F fill:#FFE4E1,stroke:#D13438

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CAC/PIV Authentication

Entra ID Configuration

# Configure certificate-based authentication
New-MgOrganizationCertificateBasedAuthConfiguration `
    -OrganizationId "{tenant-id}" `
    -CertificateAuthorities @(
        @{
            IsRootAuthority = $true
            Certificate = [Convert]::ToBase64String((Get-Content "dod-root-ca.cer" -Encoding Byte))
        }
    )

Conditional Access Policy

{
  "displayName": "Require CAC/PIV for Government Apps",
  "conditions": {
    "applications": {
      "includeApplications": ["All"]
    },
    "users": {
      "includeGroups": ["{gov-users-group}"]
    }
  },
  "grantControls": {
    "builtInControls": [
      "mfa",
      "compliantDevice"
    ],
    "authenticationStrength": {
      "@odata.type": "#microsoft.graph.authenticationStrengthPolicy",
      "requirementsSatisfied": "mfa",
      "allowedCombinations": [
        "x509CertificateSingleFactor"
      ]
    }
  }
}

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Continuous Monitoring

FISMA Reporting

// FISMA compliance dashboard query
SecurityBaseline
| where TimeGenerated > ago(30d)
| summarize
    Compliant = countif(ComplianceState == "Compliant"),
    NonCompliant = countif(ComplianceState == "NonCompliant")
    by ControlFamily
| extend ComplianceRate = round(100.0 * Compliant / (Compliant + NonCompliant), 2)
| order by ComplianceRate asc

Automated POA&M Generation

Plan of Action and Milestones (POA&M) for non-compliant controls:

# Generate POA&M from Defender findings
$findings = Get-AzSecurityAssessment | Where-Object { $_.Properties.Status.Code -eq "Unhealthy" }

$poam = $findings | ForEach-Object {
    [PSCustomObject]@{
        ControlId = $_.Properties.Metadata.AssessmentType
        Finding = $_.Properties.DisplayName
        Resource = $_.Properties.ResourceDetails.Id
        Remediation = $_.Properties.Metadata.RemediationDescription
        DueDate = (Get-Date).AddDays(30)
    }
}

$poam | Export-Csv "POAM-$(Get-Date -Format 'yyyyMMdd').csv"

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Implementation Checklist

• Obtain Azure Government subscription
• Complete FedRAMP authorization package
• Deploy Hub-Spoke network topology
• Configure ExpressRoute to agency network
• Implement CAC/PIV authentication
• Deploy Azure Policy FedRAMP initiative
• Configure Log Analytics for FISMA
• Enable Defender for Cloud Government
• Create IL4/IL5 workload subscriptions
• Implement continuous monitoring

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Next Steps

• Critical Infrastructure → — OT/IT convergence
• Disaster Recovery → — Multi-region resilience

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Reference: Azure Government Documentation — Microsoft Learn