Azure Firewall for centralized security - Step-by-Step Execution

Process Flow - Azure Firewall for centralized security

Start: Deploy Azure Firewall

↓

Configure Firewall Rules

↓

Route Traffic via Firewall

↓

Firewall Inspects Traffic

↓

Allow or Deny Based on Rules

↓

Log and Monitor Traffic

↓

End

This flow shows how Azure Firewall is deployed, configured with rules, routes traffic through it, inspects traffic, enforces rules, and logs activity for centralized security.

Execution Sample

Azure

1. Deploy Azure Firewall in VNet
2. Create Application and Network Rules
3. Configure Route Table to send traffic to Firewall
4. Firewall inspects and filters traffic
5. Logs are collected for monitoring

This sequence sets up Azure Firewall to control and monitor network traffic centrally.

Process Table

Step	Action	Configuration State	Traffic Behavior	Logs Generated
1	Deploy Azure Firewall	Firewall deployed in VNet	No traffic filtered yet	No logs
2	Create Rules	Rules defined (allow HTTP, deny others)	Traffic will be filtered per rules	No logs yet
3	Configure Route Table	Route sends traffic to Firewall	Traffic flows through Firewall	No logs yet
4	Traffic Inspection	Firewall active with rules	HTTP allowed, others denied	Logs start recording allowed/denied
5	Monitor Logs	Firewall running with monitoring	Traffic filtered continuously	Logs show traffic details
6	End	Firewall operational	Traffic filtered as per rules	Logs available for audit

💡 Firewall deployed and configured; traffic is filtered and logged for centralized security.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
Firewall State	Not deployed	Deployed	Deployed with rules	Deployed with rules and routing	Active and filtering	Active and filtering
Traffic Flow	Direct to VMs	Direct to VMs	Will be filtered	Routed through Firewall	Filtered by rules	Filtered by rules
Logs	None	None	None	None	Recording traffic	Recording traffic

Key Moments - 3 Insights

Why does traffic need a route table to send it through the Azure Firewall?

Because without routing, traffic goes directly to resources and bypasses the firewall. Step 3 in the execution_table shows routing configuration enabling traffic to flow through the firewall.

What happens if no rules are defined in the firewall?

Without rules (Step 1 and 2), the firewall cannot allow or deny traffic properly, so traffic might be blocked by default or flow unrestricted depending on default settings. Step 2 shows rules creation is essential.

How do logs help in centralized security?

Logs record allowed and denied traffic (Step 4 and 5), helping monitor and audit network activity centrally to detect threats or misconfigurations.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does traffic start being filtered by the firewall?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Check the 'Traffic Behavior' column in execution_table rows for when filtering begins.

According to variable_tracker, what is the state of 'Logs' after Step 3?

A None

B Recording traffic

C Partial logs

D Logs deleted

💡 Hint

Look at the 'Logs' row and the column 'After Step 3' in variable_tracker.

If the route table is not configured (Step 3 skipped), what happens to traffic flow?

A Traffic is routed through firewall anyway

B Traffic is blocked completely

C Traffic flows directly to resources, bypassing firewall

D Traffic is logged but not filtered

💡 Hint

Refer to key_moments explanation about routing importance and variable_tracker 'Traffic Flow' state.

Concept Snapshot

Azure Firewall protects your network by filtering traffic centrally.
Deploy it in a virtual network.
Create rules to allow or deny traffic.
Use route tables to send traffic through the firewall.
Firewall inspects traffic and logs activity for monitoring.

Full Transcript

Azure Firewall is a cloud service that protects your network by controlling traffic centrally. First, you deploy the firewall inside a virtual network. Then, you create rules that specify which traffic is allowed or denied. Next, you configure route tables so that network traffic flows through the firewall. The firewall inspects this traffic and applies the rules to allow or block it. Finally, it logs all traffic activity so you can monitor and audit your network security. This process ensures centralized security management for your cloud infrastructure.

Practice

1. What is the primary purpose of Azure Firewall in a cloud environment?

easy

A. To centralize network security and control traffic

B. To store large amounts of data securely

C. To provide virtual machines for computing

D. To manage user identities and access

Solution

1. Step 1: Understand Azure Firewall's role

   Azure Firewall is designed to protect cloud resources by controlling and monitoring network traffic centrally.

2. Step 2: Differentiate from other services

   Storing data, providing VMs, or managing identities are roles of other Azure services, not Azure Firewall.

3. Final Answer:

   To centralize network security and control traffic -> Option A

4. Quick Check:

   Azure Firewall = Centralized network security [OK]

Hint: Azure Firewall controls traffic centrally, not data or users [OK]

Common Mistakes:

• Confusing Azure Firewall with storage services
• Thinking it manages user identities
• Assuming it provides computing resources

2. Which subnet name is required when deploying Azure Firewall in a virtual network?

easy

A. Subnet1

B. AzureFirewallSubnet

C. FirewallSubnet

D. DefaultSubnet

Solution

1. Step 1: Recall Azure Firewall deployment requirements

   Azure Firewall requires a dedicated subnet named exactly 'AzureFirewallSubnet' for deployment.

2. Step 2: Check other options

   Other subnet names like 'FirewallSubnet' or 'DefaultSubnet' are incorrect and will cause deployment failure.

3. Final Answer:

   AzureFirewallSubnet -> Option B

4. Quick Check:

   Subnet name must be AzureFirewallSubnet [OK]

Hint: Use exact subnet name 'AzureFirewallSubnet' for firewall deployment [OK]

Common Mistakes:

• Using generic subnet names instead of required one
• Misspelling the subnet name
• Not creating a dedicated subnet for Azure Firewall

3. Given this Azure Firewall rule collection, what traffic will be allowed?

{
  "name": "AllowWeb",
  "rules": [
    {"name": "AllowHTTP", "protocol": "TCP", "port": 80, "action": "Allow"},
    {"name": "AllowHTTPS", "protocol": "TCP", "port": 443, "action": "Allow"}
  ]
}

medium

A. All traffic regardless of protocol or port

B. All TCP traffic on any port

C. Only HTTPS traffic on port 443

D. Only HTTP and HTTPS traffic on ports 80 and 443

Solution

1. Step 1: Analyze the rule collection

   The rules explicitly allow TCP traffic on ports 80 (HTTP) and 443 (HTTPS) only.

2. Step 2: Exclude other traffic

   Other ports or protocols are not allowed since no rules permit them.

3. Final Answer:

   Only HTTP and HTTPS traffic on ports 80 and 443 -> Option D

4. Quick Check:

   Rules allow TCP ports 80 and 443 only [OK]

Hint: Check ports and protocols in rules to find allowed traffic [OK]

Common Mistakes:

• Assuming all TCP traffic is allowed
• Ignoring port restrictions
• Confusing protocol types

4. You deployed Azure Firewall but traffic is not passing through. Which configuration mistake could cause this?

medium

A. Subnet name is not 'AzureFirewallSubnet'

B. Public IP address is assigned to the firewall

C. Firewall rules allow HTTP and HTTPS traffic

D. Virtual network has multiple subnets

Solution

1. Step 1: Identify deployment requirements

   Azure Firewall requires the subnet to be named 'AzureFirewallSubnet' exactly for proper routing.

2. Step 2: Understand impact of wrong subnet name

   If the subnet name is incorrect, firewall won't route traffic, causing blockage.

3. Final Answer:

   Subnet name is not 'AzureFirewallSubnet' -> Option A

4. Quick Check:

   Correct subnet name is critical for traffic flow [OK]

Hint: Check subnet name first if firewall blocks traffic [OK]

Common Mistakes:

• Assuming public IP causes blockage (it is required)
• Ignoring subnet naming rules
• Thinking multiple subnets cause traffic issues

5. You want to centralize security for multiple virtual networks using Azure Firewall. Which setup is best practice?

hard

A. Deploy separate Azure Firewalls in each virtual network without routing

B. Use network security groups only without Azure Firewall

C. Deploy one Azure Firewall in a hub virtual network and route traffic from spoke networks through it

D. Deploy Azure Firewall without a public IP address

Solution

1. Step 1: Understand centralized security architecture

   Using a hub-and-spoke model, one Azure Firewall in the hub network protects multiple spoke networks by routing traffic through it.

2. Step 2: Evaluate other options

   Deploying multiple firewalls increases cost and complexity; NSGs alone don't provide centralized control; firewall needs public IP for internet traffic.

3. Final Answer:

   Deploy one Azure Firewall in a hub virtual network and route traffic from spoke networks through it -> Option C

4. Quick Check:

   Hub-and-spoke with one firewall = centralized security [OK]

Hint: Use hub network firewall to protect multiple spokes [OK]

Common Mistakes:

• Deploying multiple firewalls unnecessarily
• Relying only on network security groups
• Omitting public IP for Azure Firewall