Infrastructure & Network Security

Software-Defined Perimeter

  • May 9, 2025
  • 0

Sherlocked Security – Software-Defined Perimeter (SDP) Architecture & Deployment

Enable Invisible, Identity-Driven Access to Internal Applications with Zero Trust Principles

1. Statement of Work (SOW)

Service Name: Software-Defined Perimeter (SDP) Design & Deployment
Client Type: Modern enterprises with hybrid or multi-cloud environments
Service Model: Architecture Design + Pilot Deployment + Advisory
Compliance Alignment: NIST SP 800-207, Zero Trust Architecture, PCI-DSS, HIPAA, ISO 27001

Scope Includes:

  • SDP Readiness Assessment & Use Case Mapping
  • Architecture & Design of SDP Control/Enforcement Plane
  • Identity-Centric Policy Configuration
  • Pilot Deployment of SDP Gateways & Connectors
  • Integration with Identity Providers, SIEM, and Endpoint Agents
  • Phased Migration from VPN to SDP

2. Our Approach

[Assessment & Use Case Scoping] → [Architecture & Policy Design] → [Pilot Deployment] → [Integration] → [Phased Rollout & Optimization]

3. Methodology

  • Assessment & Planning

    • Identify users, devices, and applications to be protected
    • Evaluate current remote access solutions (e.g., VPN, bastion)
    • Map use cases: developer access, 3rd-party vendor access, secure SaaS access

  • SDP Architecture Design

    • Define control plane (policy engine, broker, identity store)
    • Define data plane (gateway/enforcement points)
    • Choose deployment mode: agent-based, browser-based, or agentless

  • Identity Integration

    • Integrate with SSO/IdP (Azure AD, Okta, Ping)
    • Leverage MFA and device posture as access criteria
    • Map users to logical access policies (RBAC or ABAC)

  • Connector & Gateway Deployment

    • Deploy connectors behind firewall to expose internal apps without direct access
    • Use outbound-only connections to maintain invisibility
    • Configure policy enforcement based on identity + device + location

  • Policy Configuration

    • Define per-user and per-app access policies
    • Ensure least privilege access and session-level enforcement
    • Integrate with SIEM for logging and alerting

  • Pilot & Validation

    • Roll out to subset of users/applications
    • Validate session establishment, policy enforcement, and fallback scenarios

  • Phased Rollout & Tuning

    • Gradual transition from legacy VPN
    • Fine-tune based on usage data and feedback
    • Establish ongoing monitoring and automation playbooks

4. Deliverables

  • SDP Architecture Blueprint
  • Identity & Access Policy Matrix
  • Gateway/Connector Configuration Guide
  • Integration Documentation (IdP, SIEM, MDM)
  • User Onboarding SOP
  • Pilot Rollout Report with Observations
  • Transition Plan from VPN
  • Admin Playbook with Monitoring and Troubleshooting

5. Client Requirements

  • Inventory of internal applications to secure
  • Existing Identity Provider (SSO/MFA-enabled)
  • Application topology and hosting environment (on-prem/cloud)
  • Firewall and DNS access for connector deployment
  • User groups and access levels per application
  • Buy-in for phased rollout (pilot group)

6. Tools & Technology Stack

  • SDP Platforms: Zscaler Private Access (ZPA), Twingate, Appgate SDP, Cloudflare Zero Trust, Banyan Security
  • Identity Providers: Okta, Azure AD, PingID, Duo
  • SIEM: Splunk, Sentinel, QRadar
  • Optional: Endpoint security tools, MDM, EDR, or posture agents

7. Engagement Lifecycle

  1. Discovery & Assessment
  2. SDP Architecture Design
  3. Connector & Gateway Deployment
  4. Identity & Policy Configuration
  5. Pilot Testing & Feedback
  6. Phased Rollout
  7. Decommissioning Legacy VPN
  8. Handover & Admin Training

8. Why Sherlocked?

Feature Advantage
Zero Trust by Design Built on NIST ZTA principles with identity-first access
Vendor-Agnostic Expertise Experience across major SDP providers
Seamless VPN Migration Proven roadmap for reducing dependency on legacy VPNs
Compliance-Aligned Helps meet ZTA mandates and security control frameworks

9. Case Studies

FinTech SaaS – VPN Replacement for DevOps Teams

Problem: Legacy VPN gave all-or-nothing access, no app-level control
Solution: Zscaler Private Access deployed for identity-based access to internal dev tools
Outcome: Access reduced to per-app basis; 90% drop in VPN tickets and faster onboarding

Healthcare SaaS – 3rd Party Access to Patient Portals

Problem: No secure way to allow external QA vendors to test internal UAT portal
Solution: Implemented SDP with agentless browser access for temporary users
Outcome: No lateral risk; access revocable instantly via identity policy

10. SOP – Standard Operating Procedure

  1. Discovery

    • Inventory users, apps, and current remote access paths

  2. Architecture Setup

    • Design control plane, gateways, and policy flow

  3. Identity Integration

    • Connect to IdP, enforce MFA, map users to roles

  4. Connector Deployment

    • Deploy behind firewall, register with SDP broker

  5. Policy Creation

    • Define user-device-app-location-based policies

  6. Pilot Rollout

    • Onboard test users, monitor behavior, collect feedback

  7. Full Rollout

    • Migrate users and deprecate VPN as confidence grows

  8. Monitoring & Optimization

    • Integrate with SIEM, tune access and posture logic

11. SDP Security & Access Checklist

  • [ ] Identity integrated with MFA
  • [ ] Device posture check enabled
  • [ ] Internal apps hidden from public exposure
  • [ ] Connector deployed with outbound-only comms
  • [ ] Role-/attribute-based policies applied
  • [ ] SIEM logging enabled for all sessions
  • [ ] Pilot group defined and tested
  • [ ] VPN phase-out plan documented

Optional Enhancements

  • Just-In-Time (JIT) Access Control
  • Session Recording & Watermarking
  • Agentless Access for Contractors & 3rd Parties
  • Integration with CASB/DLP for SaaS data control
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