You want to use OSPF to advertise a only .\16 summary route for the SVls below to a neighbor In the same area (area 0).
E.
Suggested Answer: E
Explanation:
The goal is to configure OSPF on a router so that it advertises only a 10.1.0.0/16 summary route for the specific SVIs (VLAN 11, 12, 13, assumed to be within the 10.1.x.x range) to its OSPF neighbors within the same area (Area 0).
OSPF Intra-Area Behavior: A fundamental principle of OSPF (link-state protocols) is that all routers within the same area must have an identical Link State Database (LSDB) for that area. This means all routers learn about all the specific networks (Type-1 Router LSAs, Type-2 Network LSAs) within their area. OSPFv2 does not support summarizing routes in a way that hides specific network LSAs from other routers within the same area. Summarization occurs only at area boundaries (by ABRs using Type-3 Summary LSAs via the area range command) or for external routes redistributed into OSPF (by ASBRs using Type-5 External LSAs via the summary-address command).
Analysis of Options:
A) area 0 range 10.1.0.0/16: This command is used on an Area Border Router (ABR) to summarize routes originating from Area 0 when advertising them into another area (e.g., the backbone). It does not affect LSA flooding within Area 0. It also includes redistribute connected, which is unrelated here.
B) summary-address 10.1.0.0/16: This command is used on an Autonomous System Boundary Router (ASBR) to summarize external routes being redistributed into OSPF. It is not used for summarizing internal OSPF routes like SVIs defined within an OSPF area.
C) & D) summary-address 10.1.0.0/16: Same issue as B; incorrect command for summarizing internal OSPF routes.
E) area 0 range 10.1.0.0/16: Similar to A, this uses the area range command. It correctly shows the SVIs configured for OSPF Area 0 first. However, like A, this command performs inter-area summarization on an ABR and does not suppress the specific LSAs within Area 0.
Conclusion: The question asks for something that OSPFv2 cannot do: advertise only a summary route within the same area while suppressing specifics. Therefore, none of the configurations will achieve the exact stated outcome. However, if the question is flawed and intends to ask which configuration uses the correct command structure for summarizing internal OSPF routes (even if only effective between areas), then the area range command is the relevant one. Both A and E use this command. Option E is slightly better structured as it shows the interfaces being added to OSPF Area 0 first. Assuming this is the intended direction despite the impossibility of the specific request, E is the most plausible choice among the given options.
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