350-501 · Question #286
Refer to the exhibit. An engineer started to configure a router for OSPF. Which configuration must the engineer perform on the router without changing any interface configuration so that the router…
The correct answer is A. router(config)# router ospf 11. To establish an OSPF neighbor relationship without altering interface configurations, the engineer must enable OSPF globally and specify the network using the network command under the OSPF router configuration.
Question
Refer to the exhibit. An engineer started to configure a router for OSPF. Which configuration must the engineer perform on the router without changing any interface configuration so that the router establishes an OSPF neighbor relationship with its peer?
Options
- Arouter(config)# router ospf 11
- Brouter(config)# interface ethernet 1/1
- Crouter(config)# interface ethernet 1/1
- Drouter(config)# interface ethernet 1/1
How the community answered
(48 responses)- A88% (42)
- B4% (2)
- C2% (1)
- D6% (3)
Why each option
To establish an OSPF neighbor relationship without altering interface configurations, the engineer must enable OSPF globally and specify the network using the `network` command under the OSPF router configuration.
After initiating the OSPF process with `router ospf 11`, the `network 10.10.12.0 0.0.0.255 area 0` command is essential. This command enables OSPF on all interfaces within the specified subnet (10.10.12.0/24) and assigns them to Area 0, allowing for neighbor discovery and routing information exchange without requiring direct OSPF configuration on the interface itself.
Configuring `passive-interface ethernet 1/1` prevents neighbor discovery on that specific interface, which is contrary to the goal of establishing a neighbor relationship.
This configuration includes `passive-interface default` and then attempts to un-passify `ethernet 1/1`, but crucially, it lacks the `network` command under the OSPF process to include the interface's subnet in the OSPF routing domain, which is necessary for neighbor establishment.
The question explicitly states "without changing any interface configuration," making direct commands like `ip ospf 11 area 0` under the interface configuration mode an invalid approach.
Concept tested: OSPF basic configuration for neighbor adjacency
Source: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/15-mt/iro-15-mt-book/iro-cfg.html
Topics
Community Discussion
No community discussion yet for this question.