VNet creation and address space in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding VNet Address Space Overlaps

You have two Azure Virtual Networks (VNets). VNet A has the address space 10.0.0.0/16. VNet B has the address space 10.0.1.0/24. What will happen if you try to peer these two VNets?

A The peering will succeed because 10.0.1.0/24 is a subset of 10.0.0.0/16, so they are compatible.

B The peering will fail because the address spaces overlap, which is not allowed in VNet peering.

C The peering will succeed but traffic between VNets will be blocked due to overlapping address spaces.

D The peering will succeed only if you enable gateway transit on both VNets.

💡 Hint

Think about whether overlapping IP ranges are allowed in VNet peering.

Azure does not allow peering between VNets that have overlapping IP address spaces. Since 10.0.1.0/24 is within 10.0.0.0/16, the address spaces overlap, so peering will fail.

❓ Configuration

intermediate

Choosing a Valid Address Space for a New VNet

You want to create a new Azure VNet in a subscription that already has a VNet with address space 192.168.0.0/24. Which of the following address spaces can you assign to the new VNet without causing conflicts?

A 192.168.1.0/24

B 192.168.0.128/25

C 192.168.0.0/23

D 192.168.0.64/26

💡 Hint

Check if the new address space overlaps with the existing 192.168.0.0/24 range.

192.168.1.0/24 does not overlap with 192.168.0.0/24, so it is a valid choice. The other options overlap with the existing VNet's address space.

❓ Architecture

advanced

Designing VNet Address Spaces for Multi-Region Deployment

You are designing VNets for a multi-region Azure deployment. You want to avoid address space conflicts and allow future peering between VNets. Which approach is best for assigning address spaces?

A Use overlapping address spaces but rely on network security groups to isolate traffic.

B Assign the same address space to all VNets in different regions to simplify routing.

C Assign non-overlapping, contiguous CIDR blocks to each VNet, for example, 10.0.0.0/16 for region 1 and 10.1.0.0/16 for region 2.

D Assign random address spaces without coordination and fix conflicts when they arise.

💡 Hint

Think about how to avoid conflicts and enable peering in the future.

Assigning non-overlapping, contiguous CIDR blocks per region avoids conflicts and allows easy peering and routing between VNets.

❓ security

advanced

Impact of Overlapping Address Spaces on Network Security

You have two VNets with overlapping address spaces that are connected via VPN Gateway. What is a likely security risk in this scenario?

A Traffic between VNets will be encrypted, so there is no security risk.

B VPN Gateway will prevent any communication between VNets with overlapping address spaces.

C Network security groups will automatically block all traffic between overlapping VNets.

D Overlapping address spaces can cause traffic to be misrouted, potentially exposing sensitive data to the wrong VNet.

💡 Hint

Consider what happens when IP addresses overlap in different networks.

Overlapping address spaces can cause routing confusion, leading to traffic being sent to unintended destinations, which is a security risk.

❓ service_behavior

expert

Behavior of Azure VNet with Multiple Address Spaces

You create an Azure VNet and assign two address spaces: 10.0.0.0/16 and 10.1.0.0/24. You then create a subnet with address range 10.1.0.0/25. What is the behavior of this subnet within the VNet?

A The subnet is valid and usable because its address range is within one of the VNet's address spaces.

B The subnet is invalid because subnets cannot be created from the second address space of a VNet.

C The subnet overlaps with the VNet's primary address space and will cause deployment failure.

D The subnet must be larger than /24 to be valid within the VNet.

💡 Hint

Think about how VNets support multiple address spaces and subnet creation.

Azure VNets can have multiple address spaces. Subnets can be created from any of these address spaces as long as they do not overlap with other subnets.