Enabling OSPFv3 on an interface — selecting the correct IOS command Which command enables OSPFv3 for IPv6 on an interface and assigns it to area 0 on a Cisco router?

Introduction / Context:
Open Shortest Path First version 3 (OSPFv3) is the IPv6-capable iteration of OSPF. On Cisco IOS, OSPFv3 is activated per interface with a process ID and an area assignment. Choosing the correct command ensures the interface participates in the link-state domain and exchanges LSAs with neighbors.

Given Data / Assumptions:

• We want to enable OSPFv3 on a specific interface.
• Area 0 (the backbone) is the intended area.
• Standard IOS syntax is in use.

Concept / Approach:
OSPFv3 is configured per interface using ipv6 ospf area . Unlike OSPFv2 for IPv4, which commonly uses network statements under the routing process, OSPFv3 relies on explicit interface activation. Both area 0 and area 0.0.0.0 are valid representations of the backbone area.

Step-by-Step Solution:
Enter interface configuration mode for the target interface.Issue: ipv6 ospf 10 area 0.0.0.0 (or area 0).Verify neighbor formation with show ipv6 ospf neighbor and check LSAs with show ipv6 ospf database.

Verification / Alternative check:
Confirm that the interface shows “Network Type” and that Hello packets are exchanged to FF02::5 and FF02::6 multicast groups.

Why Other Options Are Wrong:

• B/C/E: These commands are for RIPng or EIGRPv6, not OSPFv3.
• D: no shutdown under an OSPF process context is not how OSPFv3 is activated. OSPFv3 process creation is separate and interface-based activation is required.

Common Pitfalls:
Trying to use IPv4 OSPF network statements for IPv6 OSPFv3. That method does not activate OSPFv3 on interfaces in classic IOS.

Final Answer:
Router1(config-if)# ipv6 ospf 10 area 0.0.0.0