ATG VPN Exit Playbook

ATG VPN Exit Playbook

Executive Summary

This playbook provides a comprehensive, vendor-neutral strategy for retiring VPN infrastructure and transitioning to a Zero Trust architecture.

ATG enhances this approach through the 3|29™ Performance Standard, SOC services, and preferred deployment alignment with leading Zero Trust and Secure Access technologies—including Zscaler—when appropriate.

This document is designed for mid-market organizations who require high performance, accountability, and secure modernization at scale. 

ATG’s 3|29™ Performance Standard

3 Rings. 29 Minutes. First Resolution.

Every ATG engagement is powered by:

  • Every call answered within 3 rings
  • Every ticket responded to within 29 minutes
  • Every issue handled by a U.S.-based First Resolution Technician (Level II/III)

3|29™ ensures speed, precision, and accountability throughout Zero Trust transformation and VPN exit projects, reducing delays, escalations, and risk exposure.

1. The State of VPN Risk

VPNs have become one of the most targeted attack vectors. Risks include:

  • Exploitable public-facing VPN gateways
  • Credential theft and brute-force attacks
  • Lateral movement inside networks
  • Ransomware propagation
  • Third-party compromise via shared VPN tunnels
  • Performance bottlenecks and user frustration
  • Heavy operational burden from patching and maintaining appliances

Modern organizations increasingly treat VPNs as legacy technology requiring replacement with Zero Trust architectures. 

2. Why Zero Trust Is the Successor to VPN

Zero Trust eliminates the idea of implicit trust. Key shifts include:

  • Users connect directly to applications, not networks
  • Access is identity- and context-based
  • Applications are not exposed to the internet
  • Lateral movement becomes impossible
  • Continuous verification replaces one-time authentication

This model delivers dramatically improved performance, visibility, and security across hybrid work environments. 

3. Zero Trust Architecture Overview (Vendor-Neutral + Preferred Technology Alignment)

Core Zero Trust capabilities include:

  • Identity-based access control
  • Application-level segmentation
  • Device posture verification
  • Continuous authentication
  • Policy-driven traffic inspection
  • Cloud-delivered access at scale

While vendor-neutral, ATG frequently integrates leading Zero Trust platforms—including Zscaler Zero Trust Exchange—when it accelerates outcomes or aligns with client environments.

4. Zero Trust Migration Blueprint

A complete VPN exit requires a structured sequence:

  1. Application Discovery and Mapping
  2. Identity & Access Integration (SSO/MFA/IdP)
  3. Segmentation and Policy Definition
  4. Deployment of Access Brokers / Connectors
  5. Pilot Programs with key user groups
  6. Phased Rollout across departments and vendors
  7. Full VPN Decommissioning & Network Simplification 

5. ATG’s Five-Phase Zero Trust Transformation Framework

ATG uses an engineered, performance-driven methodology:

PHASE 1 — ASSESS

  • Inventory apps, access paths, VPN dependencies
  • Evaluate identity maturity and device posture
  • Map user groups and third-party requirements

PHASE 2 — DESIGN

  • Build Zero Trust policies, segmentation models
  • Establish identity and device posture requirements
  • Define governance and operational workflows

PHASE 3 — PILOT

  • Validate access flows and user experience
  • Adjust segmentation boundaries
  • Harden authentication and posture enforcement 

PHASE 4 — SCALE

  • Expand access across all users and apps
  • Integrate third parties using secure, least-privileged access
  • Remove legacy dependencies

PHASE 5 — OPTIMIZE

  • Continuous monitoring and tuning via ATG SOC
  • Performance enhancements
  • Governance and compliance reporting

6. Application Access Mapping Template

Every Zero Trust journey starts with an accurate inventory. Mapping includes:

  • Application Name
  • Owner / Department
  • Authentication Method
  • Dependencies (DBs, APIs, services)
  • Required User Groups
  • Data Sensitivity Classification
  • Risk Tier 

This informs segmentation and least-privileged access modeling. 

7. Securing Third-Party Access in Zero Trust

Traditional vendor VPN tunnels introduce outsized risk.

Zero Trust replaces vendor VPN tunnels with:

  • Clientless access or limited-scope connectors
  • Role-based, per-application access
  • Device posture enforcement
  • Time-bound and audited sessions
  • Elimination of shared credentials

This drastically reduces supply chain attack surfaces.

8. Zero Trust Segmentation Strategy

Segmentation shifts from network-level boundaries (subnets, VLANs, firewalls) to:

  • Identity-based segmentation
  • Application groups
  • Role-based access policies
  • Dynamic posture-based controls

This eliminates lateral movement and reduces breach blast radius. 

9. ATG SOC Services (Integrated with Zero Trust)

ATG operates U.S.-based SOC capabilities that strengthen Zero Trust deployments:

  • 24/7 Monitoring & Alerting
  • Endpoint Detection & Response (EDR) Management
  • Vulnerability Monitoring & Attack Surface Management

These services reduce dwell time, accelerate incident response, and provide continuous posture visibility.
SOC operations also validate segmentation effectiveness and identity governance compliance over time. 

10. 90-Day Zero Trust Implementation Roadmap

DAY 1–30

  • Assessment, mapping, identity integration
  • Deploy initial access brokers
  • Begin segmentation framework

DAY 31–60

  • Pilot with IT and targeted user groups
  • Validate UX, refine policies
  • Expand segmentation

DAY 61–90

  • Broad rollout
  • Retire VPN dependencies
  • Shift monitoring to SOC and finalize governance

11. VPN Decommissioning Framework

Once Zero Trust is operational, ATG coordinates complete VPN retirement:

  • Decommission concentrators and gateways 
  • Remove firewall rules and ACLs 
  • Disable split tunnels and legacy routes 
  • Update identity/provider configurations 
  • Document new secure access architecture

The result is a smaller attack surface and reduced operational overhead. 

12. KPIs & Success Metrics

To measure Zero Trust maturity and VPN exit success:

  • Reduction in attack surface and exposed services
  • Reduction in help desk tickets and remote access failures
  • Application performance improvements
  • Increased segmentation coverage
  • Shorter dwell time via SOC event detection
  • Reduction in third-party access risk

13. Budget & Operational Considerations

Zero Trust dramatically simplifies infrastructure. Benefits include:

  • Consolidated access tools
  • Reduced hardware refresh cycles
  • Lower management overhead
  • More predictable operational costs

ATG assists in license planning, cost modeling, and modernization budgeting to ensure alignment with business growth.

14. Preferred Partner Alignment (Option B & C)

ATG remains vendor-neutral, but frequently deploys industry-leading Zero Trust platforms—including Zscaler—based on:

  • Performance
  • Cloud footprint
  • Application landscape
  • Compliance requirements

This hybrid approach ensures clients benefit from proven technology while maintaining open, flexible architectures. 

15. The ATG Advantage

ATG differentiators include:

  • 3|29™ Performance Standard for all engagements
  • U.S.-based First Resolution Technicians
  • Deep expertise in Zero Trust transformations
  • Integrated SOC monitoring and continuous governance
  • Accelerated deployment aligned to mid-market needs
  • Proven success in regulated and high-performance environments

ATG delivers secure access modernization with unmatched speed, precision, and accountability.

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