Subnets within a VNet in Azure - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a subnet in the context of an Azure Virtual Network (VNet)?

A subnet is a smaller network segment within a Virtual Network (VNet) that divides the VNet's IP address space into smaller, manageable sections. It helps organize and secure resources by grouping them logically.

beginner

Why do we use subnets inside a VNet?

Subnets help separate resources for security, control traffic flow, and organize resources by function or department. They also allow applying network security rules and routing policies at a smaller scale.

intermediate

How does the IP address range of a subnet relate to the VNet's IP address range?

The subnet's IP address range must be a subset of the VNet's IP address range. This means the subnet's addresses come from the larger pool defined by the VNet.

beginner

Can subnets in the same VNet communicate with each other by default?

Yes, subnets within the same VNet can communicate with each other by default without extra configuration, unless network security groups or other rules block the traffic.

intermediate

What is a Network Security Group (NSG) and how does it relate to subnets?

A Network Security Group (NSG) is a set of security rules that control inbound and outbound traffic. NSGs can be applied to subnets to control traffic for all resources inside that subnet.

What must a subnet's IP range be in relation to its VNet's IP range?

A A subset of the VNet's IP range

B Completely outside the VNet's IP range

C Exactly the same as the VNet's IP range

D Larger than the VNet's IP range

A subnet's IP range must be a subset of the VNet's IP range to fit inside the larger network.

By default, can resources in different subnets within the same VNet communicate?

A No, they are isolated by default

B Yes, without extra configuration

C Only if they share the same IP address

D Only if they are in different VNets

Subnets within the same VNet can communicate by default unless blocked by security rules.

What Azure feature can you use to control traffic to and from a subnet?

A Azure Blob Storage

B Virtual Machine Scale Set

C Network Security Group (NSG)

D Azure Functions

Network Security Groups (NSGs) allow you to set rules controlling traffic at the subnet level.

What is the main purpose of dividing a VNet into subnets?

A To create multiple VNets

B To increase internet speed

C To reduce storage costs

D To organize and secure resources

Subnets help organize resources and apply security controls within a VNet.

Which of the following is true about subnets in Azure VNets?

A They share the VNet's address space but have their own smaller ranges

B They must have overlapping IP ranges

C They cannot have any security rules applied

D They are completely independent networks

Subnets use smaller IP ranges within the VNet's overall address space.

Explain what a subnet is and why it is used inside an Azure Virtual Network.

Think about how a big neighborhood is divided into smaller blocks.

Describe how Network Security Groups (NSGs) work with subnets in Azure.

Imagine a security guard controlling who enters or leaves a block.