Cisco CCNA Single-Area OSPFv2 Configuration 5

Question 1

An OSPFv2 router advertises a network as O (OSPF intra-area) in the routing table. What does this indicate?

Accepted Answer

The route originated from within the same OSPF area as the receiving router

Answer

The 'O' code in the routing table indicates an OSPF intra-area route, meaning the source is in the same area as the router.

Question 2

Which OSPF timer must match between two routers for them to become neighbors?

Accepted Answer

Dead interval

Answer

Both the Hello interval and Dead interval must match between OSPF neighbors; mismatched Dead intervals prevent adjacency formation.

Question 3

A router is configured with 'network 0.0.0.0 255.255.255.255 area 0' under 'router ospf 1'. What is the result?

Accepted Answer

All active interfaces on the router participate in OSPF area 0

Answer

Using 0.0.0.0 with wildcard 255.255.255.255 matches all IP addresses, enabling OSPF on every active interface.

Question 4

What does the 'show ip ospf interface brief' command display?

Accepted Answer

Interface, area, IP address, cost, neighbor count, and DR/BDR information

Answer

This command shows a concise table of all OSPF-enabled interfaces with their area, cost, state, and neighbor counts.

Question 5

An administrator wants OSPF to use a specific router ID of 1.1.1.1 without configuring a loopback interface. Which command achieves this?

Accepted Answer

router-id 1.1.1.1 under router ospf

Answer

The 'router-id' command under 'router ospf' explicitly sets the OSPF router ID to the specified value.

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