Infrastructure & Network Security

Network Architecture Review

  • May 9, 2025
  • 0

Sherlocked Security – Network Architecture Review

Assess and Fortify Your Network Design to Maximize Security and Operational Resilience

1. Statement of Work (SOW)

Service Name: Network Architecture Review
Client Type: Enterprises, Critical Infrastructure, Financial Institutions, Healthcare Providers
Service Model: Project-Based Assessment & Retainer Advisory
Compliance Alignment: NIST 800-53, ISO/IEC 27001, PCI-DSS, HIPAA, CIS Controls

Network Architecture Review Covers:

  • Evaluation of current network design and segmentation
  • Identification of security gaps, misconfigurations, and exposure points
  • Review of firewall rules, VLAN structures, and access control models
  • Assessment of network devices (routers, switches, firewalls, load balancers)
  • Cloud, hybrid, and on-premises network topology assessments
  • Recommendations for zero trust architecture, segmentation, and hardening
  • Compliance gap identification and remediation planning

2. Our Approach

[Information Gathering] → [Topology Mapping] → [Security Review] → [Compliance Assessment] → [Risk Analysis] → [Improvement Planning] → [Reporting & Recommendations]

3. Methodology

  • Network Discovery: Collect existing documentation, logical and physical network diagrams, and inventory of all devices and systems.
  • Topology Mapping: Map the current network architecture, including segmentation zones, DMZs, and trust boundaries.
  • Configuration Review: Review device configurations for routers, switches, firewalls, and other appliances to identify weaknesses and inconsistencies.
  • Access Control Validation: Examine ACLs, firewall rules, and role-based access controls to ensure proper segmentation and minimal privilege.
  • Traffic Flow Analysis: Analyze network flows to identify unauthorized communication paths or unprotected interfaces.
  • Cloud Network Integration: Review cloud-native networking (e.g., VPCs, peering, gateways, NSGs) for secure integration with on-premises infrastructure.
  • Security Posture Assessment: Assess resilience against lateral movement, insider threats, and external intrusion based on network design.
  • Compliance Check: Align findings with applicable frameworks (NIST, ISO, PCI-DSS) to identify compliance gaps.
  • Recommendations: Provide prioritized, actionable steps to improve network security, reliability, and scalability.

4. Deliverables to the Client

  1. Network Architecture Assessment Report: Detailed report outlining the current network design, security posture, and identified risks.
  2. Configuration Review Summary: Documentation of issues in network device configurations and recommendations for remediation.
  3. Compliance Gap Analysis: Identification of non-conformities with security frameworks and industry standards.
  4. Risk Heat Map: Visual representation of critical, high, medium, and low risks across network zones.
  5. Improved Network Design Recommendations: A set of actionable design improvements, including segmentation, redundancy, and zero-trust principles.
  6. Executive Summary: A high-level, business-focused summary of the review, risks, and recommendations for senior leadership.

5. What We Need from You (Client Requirements)

  • Network Diagrams: Current logical and physical network diagrams.
  • Device Configurations: Access to configuration files for routers, firewalls, and switches.
  • Access to Management Consoles: For verification of security settings and access control policies.
  • Inventory of Assets: Network asset inventory including IP ranges, DNS mappings, and system roles.
  • Policy Documents: Existing network security policies, segmentation strategies, and compliance objectives.
  • Stakeholder Interviews: Availability of network architects or administrators for clarification and discussions.

6. Tools & Technology Stack

  • Network Analysis & Mapping:
    • Nmap, NetBox, SolarWinds Network Topology Mapper, Draw.io
  • Firewall & Config Review:
    • FireMon, Tufin, Cisco Security Manager, Panorama (Palo Alto)
  • Traffic Flow Monitoring:
    • Wireshark, NetFlow Analyzer, ntopng, Zeek
  • Cloud Networking Tools:
    • AWS VPC Flow Logs, Azure NSG Flow Logs, GCP Network Intelligence Center
  • Compliance & Risk:
    • Tenable Nessus, Qualys, OpenSCAP, NIST CSF Tools

7. Engagement Lifecycle

  1. Kickoff & Scoping: Initial briefing, collection of documentation, and understanding of network objectives.
  2. Network Discovery: Collection and analysis of topologies, configurations, and inventory.
  3. Security Review: In-depth review of configurations, segmentation, and access controls.
  4. Traffic & Flow Analysis: Evaluate inter-zone and intra-zone traffic for anomalies or misconfigurations.
  5. Cloud/Hybrid Integration Review: Ensure secure integration and boundary protection.
  6. Compliance Mapping: Identify alignment gaps with selected regulatory or best practice frameworks.
  7. Risk & Remediation Report: Deliver findings, prioritizations, and strategic recommendations.
  8. Executive Briefing: Present high-level findings to leadership for informed decision-making.

8. Why Sherlocked Security?

Feature Sherlocked Advantage
End-to-End Network Analysis Full-stack visibility across physical, virtual, and cloud networks
Configuration Deep Dive In-depth review of firewall rules, ACLs, and segmentation policies
Framework-Centric Review Aligned with NIST, ISO, PCI-DSS, and other standards
Actionable Risk Insights Prioritized risk assessment with visuals and context
Improvement Roadmap Strategic network redesign suggestions with future scalability

9. Real-World Case Studies

Segmentation & Firewall Review for Financial Services

Client: A regional bank facing repeated lateral movement attacks.
Findings: Identified flat internal network with overly permissive firewall rules.
Outcome: Recommended and implemented VLAN segmentation and updated firewall policies, reducing attack surface by 75%.

Cloud Integration Risk Exposure

Client: A healthcare provider using AWS and Azure hybrid architecture.
Findings: Misconfigured VPC peering and public-facing storage buckets created exposure points.
Outcome: Implemented secure VPC configurations, route tables, and IAM role segmentation aligned with HIPAA compliance.

10. SOP – Standard Operating Procedure

  1. Initial Assessment: Review provided documentation and schedule technical discovery calls.
  2. Discovery & Inventory: Map out all zones, devices, and interconnections.
  3. Configuration Review: Parse and analyze firewall, router, and switch configs.
  4. Security Control Evaluation: Evaluate access controls, IDS/IPS placement, and segmentation logic.
  5. Cloud/Remote Access Review: Examine VPN, cloud VPCs, and remote access configurations.
  6. Risk Identification: Cross-reference with threat models and compliance benchmarks.
  7. Documentation & Reporting: Consolidate findings into a detailed assessment report.
  8. Remediation Planning: Deliver strategic recommendations with estimated effort and impact.

11. Network Review Readiness Checklist

1. Pre-Assessment Preparation

  • [ ] Up-to-date network diagrams
  • [ ] Inventory of network devices and roles
  • [ ] Recent configuration backups (firewalls, routers, switches)
  • [ ] Access to cloud networking dashboards
  • [ ] Organizational security policies (e.g., segmentation, access control)
  • [ ] Business continuity and disaster recovery plans

2. During Engagement

  • [ ] Perform network topology validation
  • [ ] Review ACLs and firewall rules for least privilege
  • [ ] Identify open ports and exposed services
  • [ ] Validate segmentation across departments and data zones
  • [ ] Assess network monitoring coverage (IDS/IPS, logging)
  • [ ] Review cloud integration points and hybrid networking
  • [ ] Identify misconfigurations, single points of failure, and undocumented assets

3. Post-Review Actions

  • [ ] Deliver detailed risk assessment report
  • [ ] Conduct executive-level presentation of findings
  • [ ] Propose redesigned architecture (if needed)
  • [ ] Provide remediation roadmap with priorities
  • [ ] Support compliance and audit readiness initiatives
  • [ ] Recommend tools and processes for ongoing monitoring

4. Continuous Improvement

  • [ ] Schedule recurring network reviews annually or after major changes
  • [ ] Integrate network findings into security awareness and training
  • [ ] Update segmentation and firewall policies regularly
  • [ ] Align network policies with evolving threat landscape and business needs
  • [ ] Maintain compliance documentation and change control logs
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