Network Architecture Review

 

A Network Architecture Review is a structured assessment of an organization’s network design to evaluate its security posture, performance, scalability, fault tolerance, and compliance with best practices and industry standards. It's a critical activity in both proactive security and incident response planning.

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🧭 Network Architecture Review – Overview

Aspect	Details
Purpose	Identify design flaws, security weaknesses, and inefficiencies
Scope	Routers, switches, firewalls, DMZs, VLANs, segmentation, VPNs, cloud, etc.
Outcome	Risk mitigation, improved performance, and alignment with business goals

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📋 Network Architecture Review Checklist (in Table Format)

#	Review Area	Checklist Item	Risk Level	Recommendation
1	Segmentation	Is network properly segmented (e.g., user, server, DMZ, IoT, dev)?	High	Implement VLANs, firewalls, and ACLs for segmentation
2	Perimeter Security	Are firewalls, IDS/IPS, and DDoS protections in place and correctly configured?	High	Harden edge devices, enable threat feeds
3	Zero Trust Principles	Are least-privilege and microsegmentation strategies enforced?	High	Apply Zero Trust model with strict access controls
4	Firewall Rules Review	Are firewall rules minimal, documented, and periodically reviewed?	High	Eliminate unused/overly permissive rules
5	VPN Architecture	Are remote access VPNs securely configured (MFA, split-tunnel, IPsec/SSL)?	Medium	Audit VPN users and enforce MFA
6	Routing Configuration	Is routing efficient and secure (e.g., OSPF/BGP authentication, route filtering)?	Medium	Harden dynamic routing and filter routes
7	Redundancy & Failover	Are there redundant links and failover mechanisms (e.g., HA firewalls, HSRP/VRRP)?	High	Ensure high availability for critical links
8	Network Monitoring	Is real-time monitoring in place for devices, flows, and anomalies?	Medium	Deploy NDR, SNMP, and log analysis
9	Access Control	Is NAC implemented? Are switch ports locked down with 802.1X?	High	Implement NAC with dynamic VLAN assignments
10	Cloud Integration	Are hybrid/multi-cloud networks secured (e.g., VPC peering, NSGs, Transit Gateway)?	High	Use security groups, NACLs, and audit peering
11	Asset Inventory	Is there a complete inventory of network assets and their roles?	High	Use CMDB, network scanning, and auto-discovery tools
12	Device Hardening	Are routers, switches, and WAPs hardened (e.g., SSH, no SNMPv1/v2, no telnet)?	High	Apply security baselines and disable unused services
13	Logging & Alerting	Are syslogs centrally collected and correlated for response?	Medium	Send logs to SIEM; configure alerts for anomalies
14	Remote Management Security	Is out-of-band management secured (e.g., jump servers, VPN, ACLs)?	High	Segment and secure management plane
15	Wireless Network Security	Are enterprise Wi-Fi networks isolated, encrypted (WPA3), and monitored?	Medium	Use RADIUS, disable SSID broadcasting, and enforce MAC filtering
16	Cloud-Native Services	Are VPCs, subnets, security groups, and routing tables properly configured?	High	Review IaC templates and enforce CSPM policies
17	Protocol Review	Are insecure protocols (e.g., FTP, Telnet, SNMPv1) eliminated or secured?	High	Use encrypted alternatives (SFTP, SSH, SNMPv3)
18	Third-Party Connections	Are vendor/partner networks isolated, monitored, and contractualized?	High	Enforce network segmentation and regular audits
19	IPv6 Readiness	Is IPv6 enabled, and if so, is it secured (e.g., RA Guard, filtering)?	Medium	Apply IPv6 firewall policies and disable if unused
20	Compliance Mapping	Does the network support compliance with ISO 27001, PCI-DSS, NIST, HIPAA, etc.?	High	Map architecture against regulatory requirements

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🛠 Tools Commonly Used

Tool	Purpose
Nmap / Nessus	Network scanning and vulnerability assessment
Wireshark / Zeek	Deep packet inspection and protocol analysis
SolarWinds / PRTG	Network performance monitoring
Cisco Prime / NetBox	Inventory and topology mapping
Palo Alto Expedition	Firewall rule auditing and optimization
AWS Config / Azure Security Center	Cloud configuration review

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📄 Deliverables from a Network Architecture Review

Deliverable	Description
Network Topology Diagram	Logical and physical maps of network segments and devices
Gap Analysis Report	Current vs. best practice/standard alignment
Security Risk Assessment	Vulnerabilities and risks by zone, with priorities
Firewall & ACL Review Summary	Detailed evaluation of rule bases and access control effectiveness
Configuration Review Report	Best practices assessment of routing, switching, and perimeter devices
Improvement Plan	Tactical and strategic recommendations for remediation
Compliance Readiness Report	How the architecture aligns with standards like ISO 27001, PCI DSS

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Would you like a customizable network review checklist, help reviewing cloud-VPC architectures, or tools to automate diagram creation from configs (like using Nipper, Batfish, or NetBrain)?