Network Security Groups (NSG) in Azure - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Network Security Group (NSG) in Azure?

An NSG is like a security guard for your cloud network. It controls which traffic can enter or leave your virtual machines by using rules that allow or block traffic based on source, destination, port, and protocol.

beginner

How do NSG rules work in Azure?

NSG rules check network traffic against a list of rules in order. Each rule either allows or denies traffic based on conditions like IP address, port, and protocol. The first matching rule decides if the traffic is allowed or blocked.

beginner

What are the two main types of NSG rules?

Inbound rules control traffic coming into a resource. Outbound rules control traffic leaving a resource. Both help protect your cloud resources by filtering traffic.

intermediate

Where can you apply an NSG in Azure?

You can apply an NSG to a subnet or directly to a network interface of a virtual machine. This lets you control traffic at different levels in your network.

intermediate

Why is it important to have a default deny rule in NSGs?

A default deny rule blocks all traffic that does not match any allow rule. This ensures only traffic you explicitly allow can reach your resources, improving security by preventing unwanted access.

What does an NSG primarily control in Azure?

A User login permissions

B Storage account access

C Network traffic to and from resources

D Virtual machine size

NSGs control network traffic by allowing or blocking it based on rules.

Which of the following is NOT a condition you can use in an NSG rule?

A User password

B Destination port

C Source IP address

D Protocol type

NSG rules do not use user passwords; they filter traffic based on network parameters.

Where can you apply an NSG in Azure?

A On a storage account

B On a subnet or network interface

C On a database

D On a virtual machine's operating system

NSGs are applied to subnets or network interfaces to control traffic.

What happens if no NSG rule matches the network traffic?

A Traffic is denied by default

B Traffic is redirected

C Traffic is logged but allowed

D Traffic is allowed by default

NSGs have a default deny rule that blocks traffic not matching any allow rule.

Which type of NSG rule controls traffic leaving a resource?

A Firewall rule

B Inbound rule

C Access rule

D Outbound rule

Outbound rules control traffic leaving a resource.

Explain how Network Security Groups (NSGs) help protect Azure resources.

Think about how a security guard checks who can enter or leave a building.

Describe the difference between inbound and outbound NSG rules.

Consider traffic coming to and leaving from your house.