Network Security Assessment Guide

This guide explains how a network security assessment helps identify weaknesses, understand unnecessary exposure and plan prioritised improvements to reduce risk and strengthen controls.

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Method
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FAQ

What is a Network Security Assessment?

A Network Security Assessment is a structured review of the technologies, configurations and practices used to protect network access and traffic. It examines controls such as firewalls, remote access, segmentation, exposed services, management access, logging, monitoring and network infrastructure security.

Who it’s for

Organisations that need to understand network security risk, validate existing controls, prepare for major infrastructure change, or strengthen protection against unauthorised access and cyber threats.

Common use cases

Internet edge security Firewalls, gateways and exposed services protecting inbound and outbound internet connectivity
Remote access environments VPN, secure access and remote-user connectivity into corporate applications and networks
Campus access networks Switching, wireless and identity controls governing users and endpoint connectivity
Data centre east-west traffic Security controls between servers, application tiers and workloads inside the data centre
Hybrid and public-cloud networking Security across cloud connectivity, virtual firewalls and hybrid application environments
Distributed branch networks Security controls deployed across remote offices, retail sites and branch locations

Why Organisations Perform Network Security Reviews

Expose security weaknesses, confirm protections work properly and focus action on the risks that matter most.

Identify Security Weaknesses

Uncover vulnerabilities, insecure configurations and control gaps before they create avoidable security exposure.

Validate Existing Controls

Confirm firewalls, access policies and remote access protections are operating as intended across the network.

Reduce Attack Surface

Remove unnecessary exposure, services and access paths that increase the opportunities for security compromise.

Identify Configuration Risks

Find policy and device settings that weaken security or allow unintended access into the environment.

Improve Security Resilience

Strengthen the network's ability to contain threats and continue operating during security incidents.

Prioritise Remediation

Rank findings by risk so the most serious security issues are addressed first.

Common Network Security Challenges

Network security reviews commonly identify control, access and visibility issues that can weaken protection across devices, sites and services.

Misconfigured Controls

Firewall rules, VPN settings, ACLs or management interfaces may be configured incorrectly despite security technology being in place.

Excessive Attack Surface

Open ports, exposed services, broad remote access or internet-facing management can create avoidable entry points for attackers.

Unpatched Infrastructure

Outdated software and firmware can leave known vulnerabilities unresolved across switches, routers, firewalls, wireless and other devices.

Weak Access Controls

Broad administrator rights, weak authentication or permissive network access can allow reach beyond legitimate user or device requirements.

Limited Visibility

Insufficient logging, telemetry or monitoring can leave malicious traffic, policy violations and suspicious changes hard to detect.

Inconsistent Policies

Different sites, devices or platforms may enforce security requirements unevenly, creating weaker areas across the network.

Network Security Assessment

What We Assess

We assess six key areas covering the controls that protect network traffic, users, applications and connected data.

Our Assessment Scope

These core areas show how security controls are positioned and configured across the organisation’s main network paths.

01

Perimeter & Firewall Controls

  • Internet-edge firewalls
  • Inbound and outbound policy
  • NAT, published services and attack surface
02

Internal Networking & Segmentation

  • VLAN and zone boundaries
  • ACLs and firewall policy
  • East-west controls and sensitive segments
03

Remote & Secure Access

  • VPN access
  • Remote users and privileged connectivity
  • MFA and Zero Trust controls
04

Applications & Data

  • Critical applications
  • Sensitive data flows
  • Cloud, SaaS and application exposure
05

Threat Detection & Visibility

  • Firewall telemetry
  • IDS, IPS and network analytics
  • Security logging and alerting
06

Operations & Governance

  • Network-device hardening
  • Software and firmware currency
  • Policy ownership, support and incident workflows
Assessment Outcome

The assessment identifies weaknesses in network security controls, visibility and configuration, and provides a prioritised view of the remediation needed.

Network Security Assessment Approaches

Choose the approach based on whether priority lies in configuration, architecture, control operation or risk.

01
Approach

Configuration Assessment

Best suited to

Organisations needing detailed review of network-security device configurations.

Advantages
  • Identifies insecure settings and rule sprawl
  • Reveals practical remediation opportunities
Considerations

Requires authorised access to sensitive configurations.

02
Approach

Architecture Assessment

Best suited to

Environments undergoing growth, cloud adoption, data-centre change or security redesign.

Advantages
  • Evaluates trust boundaries and control placement
  • Identifies structural weaknesses configuration reviews miss
Considerations

Findings can lead to larger redesign work.

03
Approach

Control Effectiveness Assessment

Best suited to

Organisations needing evidence that deployed security controls operate as intended.

Advantages
  • Tests whether controls enforce expected policy
  • Checks detection, logging and response outcomes
Considerations

Effectiveness testing may require controlled test traffic.

04
Approach

Risk-Based Assessment

Best suited to

Organisations prioritising network-security effort around critical assets and business impact.

Advantages
  • Focuses depth on greatest business risk
  • Prioritises remediation and investment effectively
Considerations

Risk ratings rely on accurate asset criticality.

How Our Network Security Assessment Guide Works

The assessment follows a structured six-stage process, from defining scope and reviewing current controls through risk analysis, prioritisation and a clear remediation plan.

Stage 01 Discovery & Scope

Together, we define the sites, critical services and security areas in scope, along with relevant regulatory needs. We also confirm the evidence required so the assessment reflects your operational and risk priorities.

Assessment Checklist

Before the assessment begins, we will ask you to provide, share or arrange the information, access and documentation needed for the review.

Network & Security Diagrams

Provide current network and security architecture diagrams showing internet edges, firewalls, VPNs, segmentation, security zones, key applications and major data flows.

Security Device Inventory

Supply an inventory of in-scope security platforms, including firewalls, gateways, IDS or IPS, VPN, secure-access and management systems with model and software version.

Configuration & Policy Access

Arrange read-only access to configuration and policy data for in-scope security devices, including rules, objects, services, NAT, VPN and management settings.

Security Standards & Policies

Provide relevant internal security standards, network-security policies, hardening requirements, regulatory obligations and approved control frameworks used by the organisation.

Monitoring & Event Data

Share logs, alerts, events, blocked traffic, authentication failures and monitoring data from representative periods where available.

Known Risks & Incidents

Summarise known vulnerabilities, security incidents, recurring alerts, audit findings and accepted risks that may affect scope or need targeted validation.

Our Network Security Assessment Best Practices

These principles guide how we assess network security controls, access, exposure and visibility against current standards, versions and operational requirements.

Review Security Configuration Standards

We compare firewall, VPN, ACL, management, logging and security-device settings against approved or appropriate standards to identify drift and weak controls.

Check Privilege and Access

We review administrative, user and service access to find excessive permissions and unnecessary pathways that increase the impact of a compromised account or system.

Assess the Attack Surface

We assess exposed services, open ports, obsolete rules and management interfaces to identify where unnecessary external or internal exposure can be removed.

Review Software and Firmware Currency

We review appliance software, network operating systems, signatures and firmware against supported and appropriate versions to identify vulnerability and compatibility risk.

Examine Security Telemetry

We examine firewall, IDS/IPS, authentication and network-security telemetry to understand whether suspicious behaviour and control failures are visible to operations teams.

Reassess Control Effectiveness

We assess whether rules, policies and security controls still reflect current applications, users and network design, highlighting legacy access and accumulated configuration drift.

Assessment Deliverables

Following the assessment, you receive documented findings, risk records, control comparisons and a clear remediation plan based on the network security areas reviewed.

Assessment Output

Network Security Assessment

A detailed review of network security architecture, devices, firewall and access controls, management configuration, exposure, logging and other controls examined during the engagement.

Assessment Output

Security Risk Register

A prioritised record of vulnerabilities, misconfigurations, excessive access, unsupported components and other security issues, including likely impact and the affected areas.

Assessment Output

Control Gap Analysis

A structured comparison between existing security controls and the controls needed to reduce identified risks across policy, technical enforcement, monitoring and governance.

Assessment Output

Remediation Roadmap

A phased plan sequencing urgent security corrections, control improvements, lifecycle actions and longer-term architecture changes according to risk and dependency.

Why Choose Steel City Consulting for Network Security Assessments

We work with IT teams assessing network security across complex infrastructure environments. Our consultants review current requirements, identify gaps and help define practical next steps around security, resilience, configuration and operational risk.

  • Independent multi-vendor expertise Assess requirements across complex, multi-vendor infrastructure environments.
  • Decades of IT expertise Practical consultancy across architecture, deployment, optimisation and modernisation.
  • Assessment through implementation Move from findings into remediation, design and infrastructure deployment.

Network Security Assessment

Discuss Your Network Security Assessment

Tell us about your current environment, the issues you want to assess and any planned changes or projects. We’ll discuss the scope of the assessment and what you need it to establish.

From Assessment Findings to Action

Where the assessment identifies gaps or improvement opportunities, Steel City Consulting can support the next stage, from remediation and infrastructure design through to implementation and ongoing optimisation.

Remediation & Optimisation

Address performance, capacity, resilience, configuration and lifecycle issues.

Architecture & Design

Turn findings into a practical target architecture and prioritised plan.

Technology & Implementation

Select, size and implement infrastructure required to address identified needs.

Ongoing Optimisation & Lifecycle

Validate improvements and support future capacity, lifecycle and modernisation needs.

Planning a network security assessment?

Speak to our consultants about your current environment, assessment priorities and what you need the review to establish.

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Related Technology Guides

Network-security findings often lead into architecture, firewall modernisation, Zero Trust and segmentation work; these guides cover the related design and implementation areas.

Campus Networking Architecture & Design Guide

Understand how switching, wireless, segmentation, resilience and management are combined into a secure enterprise campus design.

Read the guide

Firewall Modernisation Guide

Explore how firewall platforms, policies, inspection, segmentation and management can be modernised around current security and connectivity requirements.

Read the guide

Zero Trust Security Implementation Guide

Review how Zero Trust controls are phased into real environments across identity, access, segmentation, devices and applications.

Read the guide

Network Segmentation Assessment Guide

Review how trust zones, east-west traffic, VLANs, VRFs, firewall policy and access boundaries are assessed across the network.

Read the guide

Related Solutions

Network-security findings can feed into firewall, SIEM/XDR, security-management and wider network-infrastructure improvements.

Network Management & Infrastructure Solutions

Design and modernise the underlying network architecture, switching, routing, management and supporting services around the risks and improvement priorities identified in the assessment.

Simplify Network Management ›

Firewalls

Modernise or reconfigure firewall platforms and policies to address segmentation, access-control, exposure and lifecycle issues identified during the security assessment.

Explore Firewalls ›

SIEM & XDR Platforms

Improve security visibility, detection and response by centralising and correlating security telemetry where the assessment identifies monitoring or incident-detection gaps.

Explore SIEM & XDR ›

Security Management

Centralise security policy, configuration, logging and operational oversight to address fragmented management, inconsistent controls or limited visibility identified during the assessment.

Simplify Security Management ›

Network Security Assessment Guide FAQ

When should we arrange a network security assessment?

A network security assessment is useful when exposure is unclear, controls have changed or you need to prioritise security improvements across the network.

It can help after a network change, during a security review or when teams need evidence for remediation planning. We examine network controls and access paths in context, so recommendations reflect how the environment is used.

Which parts of our network are most exposed to security threats?

We review internet-facing services, remote access, network boundaries and paths to sensitive systems to identify and rank areas with greater exposure.

Exposure depends on what is reachable, how it is controlled and what business services rely on it. We explain the risks we find and the operational context, helping your team decide which areas need attention first.

Could firewall or network configuration mistakes be weakening our security?

Yes, outdated rules, overly broad access or inconsistent device settings can weaken network security by leaving unnecessary paths open to sensitive systems.

We compare configurations with intended use and security requirements, looking for rules or settings that no longer have a clear purpose. Findings can be prioritised for review and remediation with the relevant service owners.

If one system is compromised, how far could an attacker move internally?

We examine network access paths and security controls to assess which internal systems could be reached after a compromised device gains access.

The review focuses on routes between user devices, servers and sensitive environments, including restrictions that may be missing or ineffective. This helps identify where segmentation, access rules or monitoring could limit the impact of a breach.

Are remote access and cloud connections creating gaps we cannot see?

We review remote access and cloud connections to identify exposed routes, inconsistent controls or unclear ownership across network, cloud and security teams.

Connections can bypass assumptions built around the internal network, particularly when access policies differ across services. We map relevant paths and controls, then highlight gaps that need coordination across network, cloud and security teams.

Would we actually detect suspicious network activity quickly enough?

We assess network monitoring coverage, alert handling and visibility to identify whether suspicious activity could be missed or investigated too slowly.

We consider what traffic is monitored, where logs are sent and how alerts reach the people responsible for response. The findings show where improved telemetry, integration or operating procedures could strengthen detection.

What should we fix first after a network security assessment?

We rank findings by exposure, likely impact, exploitability and business dependency to recommend which security actions should come first after review.

This separates urgent control gaps from longer-term improvements and makes dependencies visible. Your team can use the prioritised actions to plan remediation, assign owners and align security work with operational change windows.

Will the assessment disrupt live services, and what happens during it?

Most assessment work uses read-only configurations, diagrams and monitoring data, so live network services are not normally changed during the review.

We agree the scope and access with your team before reviewing the environment. Any active testing that could affect devices, users or service availability is discussed, authorised and scheduled separately.

What will we be able to decide once the assessment is complete?

You will have a prioritised view of network exposures, control gaps and recommended actions, with rationale to guide remediation and investment.

We explain why each issue matters, which systems or services it affects and what type of remediation may be appropriate. This gives security and infrastructure teams a shared basis for assigning work and planning investment.

Can Steel City Consulting help us act on the findings?

Yes, we can help plan and implement agreed network security improvements, source compatible solutions and support their integration and lifecycle.

We can work with your team from prioritisation through delivery, coordinating network changes with security and service requirements. Discuss your network security findings with our team to agree a practical next step.

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