From VPN Fatigue to Zero Trust Reality: The Night Our Network Faced the Storm
Scene 1: The Breach
It’s 08:47 AM on a Monday. The SOC dashboard lights up like a warning beacon:
- Unusual sign-ins from multiple geographies
- Legacy VPN tunnels spiking traffic
- Sensitive SharePoint files accessed from unmanaged devices
Your network team scrambles. The old model—VPN + perimeter firewall—is cracking under pressure. Attackers exploit split-tunnel misconfigurations, credential stuffing, and shadow IT SaaS apps. Every second counts.
Alex, the SOC lead, knows the drill:
- Check VPN logs
- Validate MFA enforcement
- Investigate suspicious IP ranges
But here’s the problem: VPN assumes trust once connected. The attacker is inside the tunnel, moving laterally. The perimeter is gone.
Scene 2: Enter Entra Global Secure Access
Instead of patching holes, Microsoft Entra GSA flips the script:
- Identity-driven access replaces network-centric trust
- Universal Conditional Access applies everywhere—cloud, on-prem, SaaS
- Traffic inspection via Microsoft’s global edge ensures compliance without latency
Within minutes:
- Risky sign-ins are blocked
- Sensitive apps require device compliance + phishing-resistant MFA
- Legacy VPN? Retired.
Why This Matters
Traditional VPNs assume trust once connected. Attackers love that. Entra GSA enforces Zero Trust:
- Verify explicitly every session
- Use least privilege for app access
- Assume breach and inspect continuously
Deep Dive: Entra GSA Architecture
Entra GSA is built on Microsoft’s global edge network, leveraging:
- Policy Enforcement Points at the edge for real-time decisions
- Integration with Entra ID for identity-based access
- Conditional Access Policies applied consistently across SaaS, private apps, and hybrid workloads
- Traffic Segmentation for compliance and performance optimization
Unlike VPN, which creates a flat network, GSA uses per-app tunnels with granular controls. Every session is evaluated against risk signals from Defender for Endpoint, Microsoft Threat Intelligence, and Entra ID Protection.
🔧 Fortytwo’s Role
We help enterprises deploy Entra GSA at scale, integrating:
- Microsoft Conditional Access policies
- Traffic segmentation for SaaS and private apps
- Telemetry into Sentinel for unified monitoring
Our services include:
- Zero Trust workshops
- Policy design and automation
- Integration with Defender and Purview for compliance
Entra GSA vs Zscaler: Key Differences
| Feature | Entra GSA | Zscaler |
| Native Identity Integration | Deep integration with Entra ID | Requires connectors |
| Policy Consistency | Same Conditional Access across all apps | Separate policy engine |
| Microsoft Ecosystem | Defender, Sentinel, Purview built-in | Third-party integrations |
| Licensing | Bundled with Microsoft Security stack | Separate subscription |
| Telemetry | Unified in Sentinel | Requires API integration |
💡 Bottom line: If you’re already in the Microsoft ecosystem, Entra GSA reduces complexity and cost while delivering Zero Trust at global scale.
Entra GSA and Zscaler – Can They Coexist?
Coexistence Is Possible
If your organization already uses Zscaler, you don’t have to rip and replace. Microsoft Entra Global Secure Access (GSA) and Zscaler can operate side by side as part of a unified Secure Access Service Edge (SASE) strategy. This approach lets you leverage the strengths of both platforms while maintaining Zero Trust principles.
How It Works
Microsoft and Zscaler offer complementary capabilities:
- Entra Internet Access can secure Microsoft 365 and internet traffic.
- Entra Private Access can handle private app traffic.
- Zscaler Internet Access can continue to manage general internet traffic if preferred.
- Zscaler Private Access can secure non-Microsoft private apps.
You can configure traffic forwarding profiles in the Microsoft Entra admin center to decide which traffic goes where. For example:
- Scenario 1: GSA handles Microsoft 365 + internet traffic; Zscaler handles private apps.
- Scenario 2: GSA handles Microsoft 365 traffic only; Zscaler handles internet + private apps.
Both clients can coexist on the same device (Windows 10/11 or macOS) with proper configuration. This requires enabling/disabling specific forwarding profiles and setting up FQDN/IP bypasses for smooth integration.
Why Coexistence Matters?
Enterprises often have existing Zscaler investments. Coexistence avoids disruption while enabling a gradual transition to Microsoft’s identity-centric SSE model. It also allows you to optimize routing for Microsoft workloads while maintaining Zscaler’s inspection for other traffic.
Extended Comparison Analysis
🚀 Deployment Complexity
Entra GSA:
Uses existing Entra ID infrastructure
Zscaler:
Requires connector appliances and separate policy configuration
⚡ Performance
Entra GSA:
Leverages Microsoft’s global edge with optimized routing
Zscaler:
Uses its own PoPs, which may add latency for Microsoft workloads
💰 Cost
Entra GSA:
Included in Microsoft E5 or Security add-ons
Zscaler:
Separate subscription, often doubling cost for enterprises already on Microsoft