Refer to the exhibit. Customer A is a small media company with two offices connected by a 512 Kbps tine. Their NY office is connected to several external partners by static routes on router R3. VoIP s

Question

Exhibit

Options

• AConfigure the ip ospf I area O command under Serial 1/1 interfaces on R2 and R3 to avoid
• BChange the OSPF router ID on either router so that the router IDs are unique.
• CConfigure the summary-address 10.10.0.0 255.255.240.0 command on R3 to optimize OSPF
• DConfigure the BGP routing protocol between R2 and R3 to control route propagation.

• A
  4% (2)
• B
  11% (6)
• C
  81% (43)
• D
  4% (2)

Explanation

Option C is correct because R3 acts as an ASBR (Autonomous System Boundary Router) redistributing multiple static routes to external partners into OSPF. Without summarization, each static route generates a separate Type 5 external LSA, wasting precious bandwidth on the already-congested 512 Kbps link. The summary-address 10.10.0.0 255.255.240.0 command on R3 aggregates those external routes into a single LSA, freeing bandwidth for VoIP and data-directly addressing the reported symptoms.

Why the distractors fail:

• A - Adding interfaces to OSPF area 0 doesn't reduce routing overhead or improve bandwidth utilization; it may actually increase LSA flooding.
• B - Duplicate router IDs would cause full adjacency or routing failures, not merely "poor quality"-and no conflict is described in the scenario.
• D - BGP is designed for inter-AS routing between large autonomous systems, not a two-office SMB; it adds complexity without solving the bandwidth problem.

Memory tip: Think "ASBR summarizes, bandwidth materializes." Whenever you see an ASBR redistributing static/external routes over a slow WAN, route summarization (via summary-address) is the OSPF tool that converts many LSAs into one, recovering link capacity for real traffic.

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