300-420 Question 5
Select 3You are tasked with designing an enterprise-wide addressing plan for both IPv4 and IPv6. The organization has multiple regional offices and requires a hierarchical addressing scheme to simplify routing and management. Each region must have its own subnet with enough address space to accommodate future growth. Which of the following principles should you follow to create a structured addressing plan?
- A
Use variable-length subnet masking (VLSM) to allocate address space based on the size of each region's network.
- B
Design the IPv4 subnet mask to allocate all available addresses in a single subnet to maximize address utilization.
- C
Use hierarchical addressing to create regional subnets for both IPv4 and IPv6 to simplify summarization.
- D
Reserve a large portion of IPv6 space for future expansion by allocating a /64 prefix to each regional network.
- E
Avoid using private IPv4 addresses to ensure global uniqueness of the addressing plan.
Show answer and explanation
Correct answers: A, C, D
Explanation
To create a structured addressing plan for both IPv4 and IPv6, it is crucial to use VLSM to allocate address space efficiently, implement hierarchical addressing to simplify routing, and follow IPv6 best practices such as using /64 prefixes for regional subnets to support future growth. These principles ensure scalability, efficient address utilization, and simplified network operations.
- A. Correct.
Using VLSM ensures efficient use of address space by allocating subnets with the exact number of required addresses, which supports scalability while preventing waste.
- B. Incorrect.
Allocating all available IPv4 addresses into a single subnet does not align with best practices for hierarchical addressing, as it complicates routing and lacks scalability.
- C. Correct.
Hierarchical addressing is critical for creating a structured addressing plan, as it simplifies route summarization and reduces the size of routing tables.
- D. Correct.
Allocating a /64 prefix to each regional network aligns with IPv6 best practices and supports future growth, as a /64 is the standard size for most subnets.
- E. Incorrect.
Avoiding private IPv4 addresses is not a best practice in enterprise networks, as private address ranges (defined by RFC 1918) are widely used and appropriate for internal addressing.