Cisco Certified Network Associate (CCNA) Practice Exam

Which command initiates an OSPFv3 configuration on a router?

1. ipv6 router ospf PROCESS NUMBER

2. ospf start

3. router ospf V3

4. begin ospf

The correct answer is: ipv6 router ospf PROCESS NUMBER

The correct command to initiate an OSPFv3 configuration on a router is "ipv6 router ospf PROCESS NUMBER." This command is essential because OSPFv3 is designed to support IPv6 networks and is structured differently from its predecessor, OSPFv2, which operates on IPv4. When using the "ipv6 router ospf" command, the "PROCESS NUMBER" serves as a unique identifier for this particular OSPF instance, allowing multiple OSPF processes to run simultaneously on the same router if needed. By entering this command in global configuration mode, the network administrator establishes the foundation for configuring OSPF routing for IPv6, including network statements and other parameters necessary for the OSPF operation. The other commands listed do not accurately initiate an OSPFv3 configuration. For example, the command "ospf start" does not follow the Cisco IOS command structure, "router ospf V3" misrepresents the proper syntax by mixing terminology, and "begin ospf" is not a recognized command in the Cisco IOS for OSPF configuration.