Firewall vs NVA

 Criteria to Determine Whether an Organization Needs a Firewall

Criteria	Explanation	Example
Internet-facing Applications	App is exposed to the internet; needs protection from attacks	A public-facing API or website
Outbound Traffic Control	Need to restrict egress (internet-bound) traffic to specific domains	Only allow servers to access updates.microsoft.com
East-West Traffic Control	You want to inspect traffic between subnets or VMs	App servers talking to DB over internal network
Threat Detection/Prevention	You want to detect malicious traffic or prevent intrusion	Malware communication blocked by threat intel
TLS/SSL Inspection	You want to decrypt and inspect HTTPS traffic	Detect if users are visiting malicious HTTPS websites
Logging & Auditing	Need visibility for compliance or governance	Log every connection attempt for audit reports
VPN/Hybrid Connectivity	You want to connect Azure to on-prem or other clouds	IPsec tunnel between Azure and branch office
Compliance Needs	Required by regulators (e.g., ISO, PCI-DSS, HIPAA)	Bank must inspect all inbound/outbound traffic

Azure Firewall Vs NVA

Use Case / Requirement	Choose Azure Firewall Premium	Choose NVA (e.g., FortiGate)
✅ Native Azure Integration	✔ Fully managed by Azure	❌ Requires manual setup & VM maintenance
✅ Need IDPS & Threat Intelligence	✔ Built-in with Premium SKU	✔ Advanced but needs configuration
✅ TLS/SSL Inspection	✔ Out of the box	✔ With more control over certificates
✅ Cost-efficient & Easy to Scale	✔ Auto-scaling and simple pricing	❌ Fixed sizing, license cost, HA config needed
❌ Need VPN/SD-WAN	❌ Not supported	✔ Built-in IPsec VPN, SD-WAN, BGP routing
❌ Complex Routing/Custom NAT	❌ Limited to what Azure supports	✔ Full flexibility with NAT, BGP, Policy routes
✅ You're cloud-first / cloud-native	✔ Best fit	❌ More effort to manage and patch NVAs
✅ Prefer Microsoft-native tooling (e.g., Sentinel)	✔ Tight integration	❌ Manual export of logs (unless using 3rd party SIEM)

Why Firewall Needed

 

How These Criteria Affect Security Posture

Area	How Firewalls Improve It
🔗 Network Segmentation	Isolates workloads, prevents lateral spread of malware
🧱 Perimeter Defense	First line of defense against public attacks (DDoS, scans, etc.)
🔍 Traffic Inspection	Blocks malicious payloads even in encrypted traffic
🚧 Access Control	Enforces only approved ports, IPs, domains — reduces attack surface
📜 Audit & Compliance	Provides logs for SOCs, SIEMs, and regulatory audits
🆘 Breach Containment	Outbound filtering and IDPS limit attacker movement and impact

Real-World Example: Without Firewall vs With Firewall

Scenario	Without Firewall	With Azure FW Premium or FortiGate
A VM is compromised via phishing	It can connect to any IP, download malware, and exfiltrate data	Outbound traffic to unknown IPs is blocked; C2 attempts flagged via Threat Intel
Developer accidentally opens RDP to the world	VM is directly exposed to brute-force attacks	Firewall blocks unsolicited RDP unless coming from whitelisted IPs
TLS traffic hides malware	Firewall can't see malicious payloads	TLS inspection identifies malware inside HTTPS traffic

Lets check the Importance of Criteria to choose the Firewall fist,

🔎 Criterion	🛡️ Why It’s Important	🚨 Security Impact
1. Internet-Facing Workloads	Any public-facing resource is exposed to threats like DDoS, port scanning, brute-force attacks.	A firewall (Azure or NVA) adds a protective perimeter, blocking unsolicited inbound traffic and enforcing L3-L7 inspection. Without it, attackers can reach directly into your app services or VMs.
2. Outbound Traffic Filtering	Servers in Azure often talk to the internet (for updates, APIs, etc.). Left uncontrolled, they can become botnet members or leak data.	Filtering outbound traffic (FQDN/port-based) ensures only approved destinations are reachable. This helps prevent data exfiltration and command & control (C2) communications during a breach.
3. TLS/SSL Inspection	Most threats now use HTTPS to hide. Without decryption, firewalls are blind to malicious payloads.	TLS inspection decrypts traffic, allowing the firewall to inspect content for malware, phishing, or data leaks — ensuring encrypted traffic isn’t a blind spot.
4. IDPS (Intrusion Detection & Prevention)	Detects and blocks known attack signatures (e.g., SQL injection, shellcode, port scans).	Helps proactively stop known threats before they hit your application or database. Azure FW Premium uses Microsoft threat feeds, NVAs have their own vendor feeds.
5. Threat Intelligence Feeds	Updated feeds of known malicious IPs, domains, and URLs help auto-block connections.	Prevents connections to known bad actors even before payloads arrive — adding a real-time first line of defense.
6. East-West Traffic Filtering	Lateral movement is a key tactic in ransomware or internal breaches.	Filtering internal subnet-to-subnet traffic limits attacker movement. Only allowing “App subnet → DB subnet” blocks unauthorized peer-to-peer or cross-app access.
7. VPN/Hybrid Connectivity	Needed to securely connect on-prem to Azure (especially for regulated workloads).	NVAs like FortiGate support site-to-site and client VPNs, creating secure encrypted tunnels. Azure Firewall does not support VPN functions — so NVAs are a must for this use case.
8. Compliance & Audit Logging	Many industries (e.g., BFSI, Healthcare) require logging every network connection and proving access controls.	Firewalls log every decision (allow/deny), which is critical for forensic investigations, SOC monitoring, and meeting audit requirements. Azure FW Premium integrates well with Azure Sentinel.
9. Familiarity with Vendor Ecosystem	Some customers already have FortiGate or Palo Alto on-prem. Extending the same tool to Azure simplifies training, licensing, and policy management.	Ensures consistency of security posture across environments — the same IPS rules, SD-WAN configs, or firewall policies can be reused, reducing risk of misconfigurations.
10. Scalability & Maintenance	Native services (Azure Firewall) scale automatically, NVAs require manual sizing and patching.	Poorly scaled or outdated NVAs could fail under attack or load, creating a security risk. Azure Firewall avoids that with automatic scaling and updates by Microsoft.

The Cost Management Framework

 

The Cost Management Framework

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🧾 1. Custom Budgeting Strategy

What: Define budgets and alerts by business unit, environment (Prod/UAT/Dev), and app groups.

Example:

• Set a monthly budget of $8,000 for the HR Application in Production.

• Alert at 80% usage via email and Teams notification.

• Dev/Test environments get auto-shutdown rules outside working hours to stay within a $2,000 cap.

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🏷️ 2. Cost Allocation Model

What: Use of resource tagging, management groups, and subscription design to map spend accurately.

Example:

• Tags like:

  • Environment=UAT

  • CostCenter=Finance

  • Application=PayrollApp

• Assign separate subscriptions for business units like Corporate Services, Operations, and Compliance to generate department-wise chargebacks.

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📊 3. Cost Visibility Dashboards

What: Configure dashboards in Azure Cost Management + Power BI (optional) for financial insights.

Example:

• A dashboard showing top 10 costliest services, monthly spend trends, and cost anomalies across regions.

• Finance can view costs broken down by app or project phase (e.g., Development vs Production).

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🛡️ 4. Governance Guardrails

What: Azure Policies & Blueprints to prevent misconfiguration and overprovisioning.

Example:

• Block provisioning of D-series VMs in Dev environments via Azure Policy.

• Enforce tagging on all resources using Environment, Owner, and Project before allowing deployment.

• Apply auto-shutdown policies for non-prod VMs using built-in policy definitions.

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💰 5. Reservation Planning Guide

What: Plan Reserved Instances and Savings Plans based on usage patterns.

Example:

• Identify that 80% of the Production environment uses D2s_v3 VMs consistently → Recommend 1-year Reserved Instance with payment upfront for max savings.

• Run Azure Advisor reports and filter for "Eligible for Reservation" to identify under-utilized resources.

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⚙️ 6. Automation Guidance

What: Use automation to manage cost via schedules and alerts.

Example:

• Azure Automation Runbook to shut down Dev VMs at 7 PM daily and start at 8 AM.

• Logic App to send cost alerts to Finance when spend crosses 90% of budget.

• Use Azure Function to auto-tag untagged resources based on naming conventions.

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📋 7. Action Tracker

What: A shared, living Excel/Power BI document or tracker to track optimization progress.

Example:

Recommendation	Status	Owner	Impact ($/mo)	Deadline
Right-size 20 UAT VMs	In Progress	Infra Team	$1,200	May 15
Implement Dev Auto-Off	Completed	DevOps	$800	Apr 30

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🔁 8. Review Cadence

What: Schedule structured monthly/quarterly cost reviews.

Example Agenda:

• Review top resource consumers

• Check compliance to budget thresholds

• Evaluate unused resources for decommission

• Plan reservations or savings

• Assign new action items

Participants: Cloud team, Application owners, Finance lead.

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🧠 9. Training and Knowledge Transfer (KT)

What: Enable Customer's internal IT, finance, and app teams to manage cloud spend effectively.

Example:

• Conduct a 1-hour workshop on using Azure Cost Management and Azure Advisor

• Share a "How to read your Azure bill" guide

• Live demo: Setting up budgets, alerts, and cost reports

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Let me know if you'd like this compiled into a presentation slide or Word/PDF format for stakeholder