300-420 Question 8
Select 2An enterprise network is planning to deploy a structured IPv4 and IPv6 addressing plan. The network consists of four departments: Sales, HR, IT, and Finance. Each department requires its own IPv4 subnet and IPv6 subnet, and the addressing plan must allow for future growth in each department. Which of the following practices should be followed when designing this addressing plan?
- A
Use Variable Length Subnet Masking (VLSM) for IPv4 to allocate subnet sizes based on department needs.
- B
Allocate a /48 IPv6 prefix to each department to ensure scalability.
- C
Use a hierarchical addressing scheme to group subnets by department and geographical location.
- D
Reuse IPv4 private address space (e.g., 10.0.0.0/8) across different departments for simplicity.
- E
Avoid reserving additional IP space for future growth to maximize current address utilization.
Show answer and explanation
Correct answers: A, C
Explanation
When designing a structured addressing plan, it is important to implement practices that ensure scalability, organization, and efficient address utilization. Using VLSM for IPv4 helps allocate address space based on specific needs without wastage. A hierarchical addressing scheme enables better organization and simplifies management and routing. Allocating excessively large prefixes (e.g., /48 for each department in IPv6) or failing to reserve space for growth can result in inefficiencies or future operational challenges.
- A. Correct.
Using VLSM allows the network to allocate IPv4 address space efficiently by assigning subnets based on the specific size requirements of each department.
- B. Incorrect.
Allocating a /48 IPv6 prefix to each department is not efficient for most enterprise networks. A /64 per subnet is the standard practice, and departments generally require fewer than /48 blocks.
- C. Correct.
A hierarchical addressing scheme ensures better organization and easier route summarization as the network grows, making it a best practice for scalability and management.
- D. Incorrect.
Reusing IPv4 private address space across departments can lead to overlapping address issues and complicate routing and troubleshooting.
- E. Incorrect.
Avoiding reservation for future growth is a poor practice as it can lead to address exhaustion and require major reconfiguration later.