Infrastructure & Network Security

Segmentation & Micro-Segmentation Review

  • May 9, 2025
  • 0

Sherlocked Security – Segmentation & Micro-Segmentation Review

Divide and Protect: Minimize Lateral Movement with Secure Network Boundaries

1. Statement of Work (SOW)

Service Name: Network Segmentation & Micro-Segmentation Review
Client Type: Enterprises, Finance, Healthcare, Manufacturing, Critical Infrastructure
Service Model: Assessment & Architecture Review / Design & Validation
Compliance Alignment: PCI-DSS 4.x, HIPAA, NIST 800-207 (Zero Trust), NERC CIP, ISO 27001

Segmentation Services Cover:

  • Macro segmentation design validation
  • Micro-segmentation policy analysis
  • East-west traffic analysis and logging
  • Firewall rule review at segment boundaries
  • Zero Trust architecture readiness
  • Tag-based segmentation in cloud environments
  • Hybrid and multi-site segmentation design

2. Our Approach

[Zone & Trust Boundary Mapping] → [Traffic Flow Baseline] → [Policy Analysis] → [Simulation & Enforcement] → [Gap Identification] → [Remediation & Redesign]

3. Methodology

  • Asset & Zone Discovery: Identify and group assets by function, sensitivity, and business role.
  • Trust Boundary Review: Map inter-zone access and validate network firewall enforcement.
  • Traffic Flow Analysis: Capture and analyze east-west flows between segments using NetFlow, logs, or traffic taps.
  • Firewall/ACL Policy Review: Examine access control configurations for overly permissive or obsolete rules.
  • Micro-Segmentation Assessment: Evaluate host-level controls (e.g., VMware NSX, Illumio, native OS firewalls).
  • Cloud & Hybrid Segmentation: Assess tag-based segmentation in AWS, Azure, GCP environments.
  • Zero Trust Readiness Check: Map policies and identity-based access against Zero Trust architecture principles.
  • Simulation & Modeling: Use tools to simulate segmentation policy changes and validate containment.
  • Policy Optimization Plan: Recommend risk-driven segmentation policies and access minimization.

4. Deliverables to the Client

  1. Segmentation Architecture Map
  2. Trust Zone Inventory
  3. East-West Traffic Flow Diagrams
  4. Firewall & ACL Rule Review Report
  5. Micro-Segmentation Policy Assessment
  6. Gap Analysis & Risk Rating
  7. Zero Trust Segmentation Scorecard
  8. Remediation & Redesign Recommendations
  9. Simulation Results (if applicable)
  10. Segmentation Governance SOP

5. What We Need from You (Client Requirements)

  • Network Topology Diagrams
  • Firewall Configurations / Rule Exports
  • Access Control Policies & Zone Definitions
  • Cloud Tagging & Security Group Policies
  • NetFlow / Packet Capture Data (if available)
  • Asset Inventory (by segment/zone)
  • Compliance Drivers (e.g., PCI-DSS, NIST ZTA)

6. Tools & Technology Stack

  • Traffic Visibility:
    • Wireshark, NetFlow/sFlow, Zeek, TAP/SPAN
  • Firewall/ACL Analysis:
    • Tufin, FireMon, AlgoSec, Nipper, Panorama, Cisco FMC
  • Micro-Segmentation Platforms:
    • VMware NSX, Illumio, Guardicore, Azure/NSG, AWS SG/NACL
  • Simulation & Modeling:
    • RedSeal, Skybox Security, Forward Networks
  • Compliance Alignment:
    • PCI-DSS Req 1.2/1.3, NIST SP 800-207, CIS v8 Controls 13 & 14

7. Engagement Lifecycle

  1. Scoping & Requirements Gathering

    • Understand business zones, compliance scope, and current segmentation strategy

  2. Discovery & Mapping

    • Identify zones, data flows, and control points (on-prem, cloud, hybrid)

  3. Traffic Analysis

    • Capture and review east-west traffic flows to detect unnecessary access

  4. Firewall & Policy Review

    • Examine rules between trust zones, data centers, cloud, and users

  5. Micro-Segmentation Assessment

    • Review hypervisor-level or agent-based segmentation capabilities

  6. Gap Analysis & Simulation

    • Model enforcement scenarios and identify segmentation weak points

  7. Remediation Design

    • Recommend new access control policies, tagging, and enforcement models

  8. Governance & SOP Development

    • Provide segmentation policy lifecycle, testing guidance, and audit SOPs

8. Why Sherlocked Security?

Feature Sherlocked Advantage
End-to-End Visibility Full analysis from macro firewall zones to hypervisor-level segmentation
Vendor-Neutral Expertise Experienced with Palo Alto, Cisco, NSX, Guardicore, Illumio, and more
Compliance-Driven Mapping Delivers segmentation aligned to PCI, HIPAA, and Zero Trust mandates
Simulated Impact Modeling Validates access changes before enforcement to prevent outages
Cloud & Hybrid Coverage Supports AWS, Azure, GCP, and on-prem multi-segment architectures

9. Real-World Case Studies

Financial Services – Micro-Segmentation Enforcement

Client: Global investment bank
Problem: Overly permissive east-west traffic in data center
Solution: Deployed NSX-based micro-segmentation based on application role
Outcome: Reduced attack surface by 75%, achieved Zero Trust maturity milestone

Manufacturing – Zone-Based Segmentation Audit

Client: Smart factory operator
Problem: OT and IT networks had overlapping access
Solution: Performed segmentation audit and VLAN redesign
Outcome: Clear separation of IT/OT traffic with firewall enforcement at zone boundaries

10. SOP – Standard Operating Procedure

  1. Zone Identification

    • Define and document trust zones (e.g., corp, prod, dev, DMZ, OT)

  2. Traffic Flow Baseline

    • Collect NetFlow or packet data between zones
    • Identify unexpected or excessive communication paths

  3. Firewall & ACL Review

    • Export and analyze inter-zone firewall rules
    • Identify broad, obsolete, or shadowed rules

  4. Micro-Segmentation Review

    • Inventory agent/hypervisor-based controls
    • Review per-host policies and group tagging logic

  5. Simulation & Validation

    • Use modeling tools to simulate enforcement impacts
    • Validate no disruption to critical apps

  6. Gap Analysis & Risk Scoring

    • Assign risk scores to exposed zones and flows
    • Prioritize based on data sensitivity and access volume

  7. Remediation & Design

    • Recommend and assist in implementing tighter policies
    • Propose Zero Trust-aligned segmentation policies

  8. Governance SOP

    • Define process for segmentation rule creation, review, and decommissioning

11. Segmentation Readiness Checklist

1. Before Engagement

  • [ ] Network and cloud architecture diagrams
  • [ ] Current firewall/ACL exports
  • [ ] List of trust zones and tagging schemes
  • [ ] Asset inventory by zone/function
  • [ ] Compliance requirements (PCI, HIPAA, etc.)

2. During Engagement

  • [ ] Traffic flow capture and analysis
  • [ ] Identify inter-zone flows and dependencies
  • [ ] Analyze segmentation enforcement points
  • [ ] Review and simulate policy changes

3. After Engagement

  • [ ] Implement segmentation recommendations
  • [ ] Update tagging and grouping logic
  • [ ] Tune or apply micro-segmentation policies
  • [ ] Audit inter-zone firewall rules

4. Continuous Improvement

  • [ ] Monitor east-west flows periodically
  • [ ] Review zone boundaries annually
  • [ ] Automate tagging and policy assignment
  • [ ] Conduct annual segmentation audits
  • [ ] Align segmentation with asset lifecycle and application onboarding
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