Comprehensive and Detailed In-Depth Explanation:
Understanding Intra-Area-Prefix-LSA (Type 9) in OSPFv3
* OSPFv3 uses the Intra-Area-Prefix-LSA (Type 9) to advertise IPv6 prefixes associated with either:
* A Router-LSA (Type 1) # Describes links and interfaces.
* A Network-LSA (Type 2) # Advertises multi-access networks (if a Designated Router exists).
* Each router generates one Intra-Area-Prefix-LSA to advertise its own IPv6 prefixes.
Prefix Analysis for Each Router
R1's IPv6 Prefixes:
* 2000:12::1/64
* 2001:12::1/64
* 2002:12::1/64
* 2003:12::/64 (Shared link with R2)
* Total Prefixes in R1's Intra-Area-Prefix-LSA = 4
# R1 advertises four prefixes in its Intra-Area-Prefix-LSA.
R2's IPv6 Prefixes:
* 2003:12::2/64 (Shared link with R1)
* Total Prefixes in R2's Intra-Area-Prefix-LSA = 1
# R2 advertises only one prefix in its Intra-Area-Prefix-LSA.
Checking Each Option:
# A. The Intra-Area-Prefix-LSA generated by R2 describes three prefixes. (# False, R2 only has one prefix).
# B. The Intra-Area-Prefix-LSA generated by R1 describes four prefixes. (# True, R1 has four prefixes).
# C. The Intra-Area-Prefix-LSA generated by R2 describes four prefixes. (# False, R2 only has one prefix).
# D. The Intra-Area-Prefix-LSA generated by R1 describes three prefixes. (# False, R1 has four prefixes).
Final Conclusion:
# B. The Intra-Area-Prefix-LSA generated by R1 describes four prefixes.
Thus, the correct answer is: B. The Intra-Area-Prefix-LSA generated by R1 describes four prefixes.