Comprehensive and Detailed In-Depth Explanation:
Understanding OSPFv3 Areas and Routing Behavior
* OSPFv3 Area Types in the Network:
* Area 1 (Stub Area): Does not accept external LSAs (Type 5) but can receive Inter-Area-Prefix- LSAs (Type 3).
* Area 2 (Common Area): Fully functional area that allows both Type 3 (Inter-Area) and Type 5 (External) LSAs.
* Area 3 (NSSA - Not-So-Stubby Area): Does not accept Type 5 (External) LSAs but allows ASBRs to inject external routes using Type 7 LSAs, which are later converted to Type 5 in other areas.
* Effect of stub no-summary Command on Area 1 (Configured on R2):
* This command prevents Type 3 LSAs from entering Area 1, meaning R4 will not learn about
2000::6/128 from other areas.
* R4 only has a default route (::/0) provided by R2 but not individual routes like 2000::6/128.
Route and Packet Flow Analysis
A: "The LSDB of R4 contains the Inter-Area-Prefix-LSA that is generated by R1 and describes 2000::6
/128." # (False)
* R4 is in Area 1 (a totally stub area), which does not receive Type 3 LSAs.
* Since 2000::6/128 is an external route from Area 2, it will not be present in R4's LSDB.
* Thus, R4 does NOT have the Inter-Area-Prefix-LSA for 2000::6/128.
# Statement A is incorrect.
B: "The path for data packets from R4 to 2000::6 is R4 -> R1 -> R5 -> R3 -> R6." # (False)
* R4 is in a totally stub area (Area 1), and it does not have a specific route for 2000::6/128.
* It only has a default route (::/0) pointing to R2.
* If R4 forwards traffic, it will send it to R2, NOT via R1, R5, and R3.
# Statement B is incorrect.
C: "The routing table of R4 does not contain the route 2000::6/128." # (True - Correct Answer)
* R4 is in a totally stub area (Area 1), meaning it only receives a default route from R2 (::/0).
* It does NOT receive specific routes like 2000::6/128.
# Statement C is correct.
D: "The path for data packets from R4 to 2000::6 is R4 -> R2 -> R6." # (False)
* While R4 does forward all unknown traffic to R2 (due to the default route), R2 will NOT directly forward to R6.
* R2 is an ABR (Area Border Router), and the actual path to 2000::6 must traverse Area 2, likely through other routers.
# Statement D is incorrect.
Final Conclusion:
# C. The routing table of R4 does not contain the route 2000::6/128.
Thus, the correct answer is: C. The routing table of R4 does not contain the route 2000::6/128.