Microsoft Entra Global Secure Access: Complete SSE/ZTNA Guide to Replace Your VPN Infrastructure

Executive Summary: Evolution Toward Microsoft SSE/ZTNA

Microsoft Entra Global Secure Access represents a decisive turning point in Microsoft's approach to network access control. This SSE (Secure Service Edge) solution integrated into the Microsoft Entra ecosystem enables organizations to gradually migrate from traditional VPN infrastructure to an authentically cloud-native Zero Trust model.

SSE/ZTNA Positioning in the Microsoft Ecosystem

Defining the Microsoft Framework

In Microsoft's approach, SSE (Secure Service Edge) refers to the convergence of network and security functions in the cloud, orchestrated by Microsoft Entra. Unlike generic market definitions, Microsoft positions Global Secure Access as a native service integrated across the entire identity and security stack.

ZTNA (Zero Trust Network Access) at Microsoft is built on three fundamental pillars:

• Explicit verification via Conditional Access
• Principle of least privilege with granular policies
• Assumption of compromise with continuous monitoring

Component Architecture

Global Secure Access comprises two complementary modules:

Internet Access (GA since March 2024):

• Protection of Microsoft 365 traffic via global points of presence
• Access control to third-party SaaS applications
• Native SSL/TLS inspection with Microsoft certificates

Private Access (Public Preview):

• Secure access to internal applications without VPN
• Lightweight connectors replacing on-premises appliances
• Native integration with Azure AD Application Proxy

Architecture Patterns and Data Flows

Pattern 1: Microsoft 365 Traffic Protection

User traffic to Microsoft 365 transits through Global Secure Access entry points, enabling:

• Real-time application of Conditional Access policies
• Content inspection and threat detection
• Latency optimization via Microsoft's global network

Pattern 2: Third-Party SaaS Access Control

Integration with Microsoft Defender for Cloud Apps enables granular control of non-Microsoft SaaS applications:

1{
2  "policy": {
3    "name": "SaaS_Access_Control",
4    "conditions": {
5      "applications": ["Salesforce", "Dropbox"],
6      "userRisk": "Medium",
7      "deviceCompliance": "Compliant"
8    },
9    "controls": {
10      "sessionControl": "Monitor",
11      "downloadRestriction": true
12    }
13  }
14}

Pattern 3: VPN Replacement via Private Access

The Private Access module establishes secure tunnels to internal applications:

• Connectors deployed in internal network segments
• Intelligent routing based on FQDN and IP ranges
• End-to-end encryption with certificate authentication

Progressive Implementation Guide

Technical and Licensing Prerequisites

Required licenses:

• Internet Access: Microsoft Entra Suite or Entra P1/P2 + supplementary module
• Private Access: Microsoft Entra Suite (recommended for complete integration)

Technical dependencies:

• Azure AD Connect or Entra Connect (hybrid environments)
• Microsoft Intune for device management
• Stable network connectivity to Azure (99.9% SLA)

Recommended Onboarding Sequence

Rollback Strategy

Operational Considerations

Logging and Observability

Primary data sources:

• Entra Sign-in Logs: Authentication and Conditional Access policies
• Global Secure Access Logs: Network traffic and user sessions
• Microsoft Sentinel: Correlation with security events

1// KQL query to analyze Private Access sessions
2MicrosoftGraphActivityLogs
3| where Category == "NetworkAccessTraffic"
4| where TimeGenerated > ago(24h)
5| summarize SessionCount = count(), UniqueUsers = dcount(UserId) by Application, bin(TimeGenerated, 1h)
6| render timechart

Performance Impact

Observed latency:

• Microsoft 365: Average 10-15% reduction thanks to network optimization
• SaaS applications: 20-30ms increase due to inspection
• Private applications: Latency equivalent to VPN with better stability

Recommended optimizations:

• Split tunneling configuration for non-critical applications
• Use of closest regional access points
• Local caching for frequently accessed resources

Microsoft Defender XDR Integration

Global Secure Access telemetry automatically enriches Microsoft Defender XDR:

• Detection of abnormal access attempts
• Correlation with endpoint and email signals
• Automated response via Microsoft Sentinel playbooks

Risks and Mitigation Strategies

Poorly Scoped Policies

Problem: Configuration too restrictive blocking access to critical applications.

Impact: Service interruption, users circumventing policies.

Mitigation:

• Mandatory pilot phase with test groups
• "Report-only" mode for minimum 2 weeks
• Exclusion groups for critical service accounts

Uncontrolled Split Tunneling

Problem: Traffic bypassing security controls via direct connections.

Impact: Threat exposure, DLP policy non-compliance.

Mitigation:

• Explicit configuration of traffic categories
• Monitoring of direct connections via Defender for Endpoint
• Conditional Access policies blocking non-compliant devices

Cloud Service Dependency

Problem: Global Secure Access service unavailability impacting application access.

Impact: Productivity loss, degraded access to internal resources.

Mitigation:

• Temporary maintenance of backup VPN connections
• Configuration of automatic failover rules
• Proactive communication to users in case of incident

Architectural Decision Matrix

Selection Criteria by Component

Internet Access - Recommended for:

• Organizations > 500 users with heavy Microsoft 365 usage
• Compliance requirements necessitating SSL inspection
• Mature Zero Trust strategy with Conditional Access deployed

Private Access - Suitable for:

• Internal web applications (HTTP/HTTPS)
• Progressive VPN user replacement
• Environments with stable Azure connectivity

Temporary VPN Maintenance - Necessary for:

• Legacy non-web applications (mainframe, proprietary protocols)
• Environments with specific regulatory constraints
• Transition phase during migration

Zero Trust Maturity Matrix

Useful Links and Official References

Microsoft Technical Documentation

• Microsoft Entra Global Secure Access - Overview (Updated: March 2024)
• Internet Access Deployment Guide (GA)
• Private Access - Preview Documentation (Public Preview)
• Conditional Access Integration (GA)

Planning Resources

• Microsoft 365 Roadmap - Global Secure Access features
• Tech Community - Global Secure Access - Experience feedback and best practices
• Microsoft 365 Message Center - Product announcements and changes

Sizing and Cost Tools

• Entra License Calculator - Cost estimation
• Azure Pricing Calculator - Additional costs (bandwidth, logs)

Technical Glossary

Conditional Access: Microsoft policy engine enabling resource access control based on contextual criteria (identity, device, location, risk).

Global Secure Access Client: Software agent deployed on workstations to route traffic via Microsoft access points.

Private Access Connector: Lightweight component deployed in internal infrastructure to establish secure connectivity to private applications.

SSE (Secure Service Edge): Convergent architecture combining network functions (SD-WAN) and security (SASE) in a unified cloud service.

Split Tunneling: Configuration allowing selective routing of certain traffic flows via Global Secure Access while maintaining direct access for other applications.

Traffic Forwarding Profile: Configuration defining which traffic categories (Microsoft 365, SaaS, private) are routed via Global Secure Access.

ZTNA (Zero Trust Network Access): Network access model based on continuous verification of identity and context, replacing the traditional network perimeter concept.