Cisco Certified Network Associate (CCNA) Practice Exam

What command is used to initiate OSPF for IPv6 on a router?

1. ipv6 router ospf

2. ipv6 router eigrp

3. router ospf

4. router eigrp

The correct answer is: ipv6 router eigrp

The command to initiate OSPF for IPv6 on a router is "ipv6 router ospf." This command is specifically designed for configuring OSPF in an IPv6 environment. When you enter this command in the router’s configuration mode, you are declaring that the router will run OSPF as the routing protocol for IPv6 networks. The command sets up the necessary processes and allows the administrator to then configure OSPF parameters such as the OSPF process ID and other related settings. Other options, like "ipv6 router eigrp," pertain to EIGRP for IPv6, which is another routing protocol and would not initiate OSPF. Likewise, the "router ospf" and "router eigrp" commands are used for IPv4 environments, as they do not include the "ipv6" specification needed for IPv6 routing configurations. Understanding the context of each command is crucial for correctly implementing OSPF in IPv6 networks.