mediumMultiple Choice
CCNP Practice Question: Examine the following configuration for a Cisco…
Examine the following configuration for a Cisco IOS-XE device:
interface GigabitEthernet0/0 ip address 10.0.0.1 255.255.255.252
ipv6 address 2001:db8::1/64 ipv6 ospf 1 area 0 !
interface GigabitEthernet0/1 ip address 192.168.1.1 255.255.255.0
ipv6 address 2001:db8:1::1/64 ipv6 ospf 1 area 0 ! ipv6 router ospf 1 router-id 2.2.2.2
Which statement is true about OSPFv3 operation?
⚠ Common exam trap
The trap here is assuming OSPFv3 uses global IPv6 addresses for adjacencies like OSPFv2 uses IPv4 addresses; candidates often forget that OSPFv3 relies on link-local addresses for neighbor formation.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
OSPFv3 will form adjacencies over both interfaces using link-local addresses.
OSPFv3 forms adjacencies using IPv6 link-local addresses (fe80::/10), not the global unicast addresses configured on the interfaces. The `ipv6 ospf 1 area 0` command enables OSPFv3 on the interface, and the router automatically uses the link-local address as the source for hello packets. The global IPv6 addresses (2001:db8::1/64 and 2001:db8:1::1/64) are used for reachability but not for neighbor establishment.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
OSPFv3 will form adjacencies over both interfaces using the configured IPv6 addresses.
Why it's wrong here
OSPFv3 forms adjacencies using link-local addresses (fe80::/10), not the configured global unicast addresses. Global addresses are reachability next hops only. The statement is tempting because the interfaces do hold global addresses, but adjacency formation relies on link-local addressing.
- ✓
OSPFv3 will form adjacencies over both interfaces using link-local addresses.
Why this is correct
OSPFv3 runs per-link over IPv6 and forms adjacencies using link-local addresses (fe80::/10), which are automatically generated on each interface. The configured global addresses are irrelevant to neighbour discovery, so adjacencies establish on both GigabitEthernet0/0 and GigabitEthernet0/1.
- ✗
OSPFv3 will only run on GigabitEthernet0/0 because the router-id is not configured for GigabitEthernet0/1.
Why it's wrong here
A single router-id configured under the OSPFv3 process applies to the whole process, so both interfaces run. The claim is tempting because per-interface router-ids exist in some protocols, but OSPFv3 uses one process-wide router-id, elected from the highest loopback or interface address.
- ✗
OSPFv3 requires an explicit network command under the OSPFv3 process to enable on interfaces.
Why it's wrong here
OSPFv3 enables per-interface using the ipv6 ospf area command, as shown; there is no network command under the OSPFv3 process. The claim is tempting because OSPFv2 uses network statements, but OSPFv3 moved interface enablement to interface configuration.
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.