CCNA IP Routing Practice Question
Exhibit
R1(config)# ipv6 route ::/0 2001:db8:ff::1
What is the operational purpose of configuring the IPv6 route ::/0?
⚠ Common exam trap
A frequent exam trap is mistaking the IPv6 default route (::/0) for a command that enables OSPFv3 or performs address translation. Some candidates incorrectly believe that the static route command configures OSPFv3 or converts link-local addresses to global unicast addresses. Another common error is interpreting ::/0 as a summary route with a /64 prefix, which it is not. Understanding that ::/0 is specifically a default route that provides a fallback path for all unknown IPv6 destinations is crucial to avoid these misconceptions.
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
✓
It provides a fallback path for unknown remote IPv6 destinations.
The configured route is a default route. In practical terms, it gives the router one simple next hop for any remote IPv6 destination that is not matched by a more specific entry. That is exactly what a small branch router often needs when it has a single upstream path. This is the same design logic as an IPv4 default route, but with IPv6 syntax and addressing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
It provides a fallback path for unknown remote IPv6 destinations.
Why this is correct
A static default route ::/0 is the IPv6 equivalent of 0.0.0.0/0, serving as the route of last resort. When the routing table contains no more-specific entry for a destination, the router forwards the packet to the next hop defined by this default route. This allows reachability to any IPv6 network not explicitly known, not just summarizing routes.
- ✗
It enables OSPFv3 on the upstream interface.
Why it's wrong here
OSPFv3 is an IPv6 routing protocol enabled in interface configuration mode with commands like `ipv6 ospf process-id area area-id`, not by a global static-route command. The statement `ipv6 route ::/0` belongs to the global configuration and simply installs a default route into the routing table. Activating OSPFv3 would require a router-id, process configuration, and neighbor relationships, none of which are implied by this command.
When this WOULD be correct
If the question were to ask about the configuration of OSPFv3 on a router and how it interacts with IPv6 routing, then selecting this option could be correct if it was stated that enabling OSPFv3 would automatically configure routes for IPv6 traffic on the upstream interface.
- ✗
It converts link-local addresses into global unicast addresses.
Why it's wrong here
The command shown is a static-route statement, not an address translation or prefix-conversion mechanism. IPv6 routing forwards packets based on destination addresses, and it never converts link-local addresses into global unicast addresses. Link-local addresses (fe80::/10) are confined to a single link and are simply not routable, so no default route could perform such a translation.
When this WOULD be correct
In a different exam scenario where the question asks about the functionality of a NAT64 device or an IPv6 transition mechanism, this option could be correct if it describes a process that translates link-local addresses for global communication. The question would need to focus on address translation mechanisms.
- ✗
It summarizes all IPv6 routes into one /64 route.
Why it's wrong here
The prefix ::/0 is the IPv6 default route, which has a prefix length of zero, not a /64 summary. A /64 network would specify 64 bits of fixed prefix, such as 2001:db8:1234:abcd::/64, and would only cover that subnet. This command does not aggregate or summarize any existing routes; it only matches traffic that has no other route and sends it to the specified next hop.
When this WOULD be correct
In a different exam scenario where the question asks about the benefits of route summarization in an IPv6 network, option D would be correct. For example, if the question stated, 'What is the advantage of summarizing multiple IPv6 routes into a single route?', then this option would be appropriate.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓It provides a fallback path for unknown remote IPv6 destinations.Correct answer▾
Why this is correct
A static default route ::/0 is the IPv6 equivalent of 0.0.0.0/0, serving as the route of last resort. When the routing table contains no more-specific entry for a destination, the router forwards the packet to the next hop defined by this default route. This allows reachability to any IPv6 network not explicitly known, not just summarizing routes.
✗It enables OSPFv3 on the upstream interface.Wrong answer — click to see why▾
Why this is wrong here
The command shown is an IPv6 static route (ipv6 route ::/0 <next-hop>), which configures a default route, not an OSPFv3 command. OSPFv3 is a dynamic routing protocol enabled via 'ipv6 router ospf' and interface-specific commands, not a static route statement.
★ When this WOULD be the correct answer
If the question were to ask about the configuration of OSPFv3 on a router and how it interacts with IPv6 routing, then selecting this option could be correct if it was stated that enabling OSPFv3 would automatically configure routes for IPv6 traffic on the upstream interface.
Why candidates choose this
Students may confuse the IPv6 static route configuration with OSPFv3 because both involve IPv6 routing. The presence of an IPv6 address or next-hop might be mistaken for an OSPFv3 neighbor or network statement, especially if they are not familiar with the exact syntax of OSPFv3.
✗It converts link-local addresses into global unicast addresses.Wrong answer — click to see why▾
Why this is wrong here
Routing does not perform address translation or conversion between address types. Link-local addresses (fe80::/10) are used for local communication and are not routable, while global unicast addresses are routable. A static route simply directs traffic based on destination, it does not modify source or destination addresses.
★ When this WOULD be the correct answer
In a different exam scenario where the question asks about the functionality of a NAT64 device or an IPv6 transition mechanism, this option could be correct if it describes a process that translates link-local addresses for global communication. The question would need to focus on address translation mechanisms.
Why candidates choose this
Test-takers might think that routing involves changing addresses, similar to NAT (Network Address Translation). The concept of link-local and global unicast addresses can be confusing, leading to the incorrect assumption that a default route converts between them.
✗It summarizes all IPv6 routes into one /64 route.Wrong answer — click to see why▾
Why this is wrong here
The route ::/0 is a default route that matches all IPv6 destinations, not a summary route. A summary route aggregates multiple more specific prefixes into a single, less specific prefix (e.g., summarizing 2001:db8:1::/48 and 2001:db8:2::/48 into 2001:db8::/32). The /0 prefix length is the least specific possible, indicating a default route, not a summary.
★ When this WOULD be the correct answer
In a different exam scenario where the question asks about the benefits of route summarization in an IPv6 network, option D would be correct. For example, if the question stated, 'What is the advantage of summarizing multiple IPv6 routes into a single route?', then this option would be appropriate.
Why candidates choose this
Students may confuse the concept of a default route (::/0) with route summarization because both involve a less specific prefix. The notation ::/0 might be misinterpreted as a summary of all IPv6 routes, but summarization typically uses a prefix length that is longer than /0 and covers a contiguous block of addresses.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
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.
Go deeper
Related to this question
Learn chapter
OSPFv3 Single-Area Configuration for IPv6
Key term
IPv4
IPv4 is the fourth version of the Internet Protocol, a set of rules that assigns unique numerical addresses to devices so they can communicate over networks like the internet.
Key term
Default route
A default route is a catch-all routing entry that tells a network device where to send packets when no specific route matches the destination address.
About these practice questions
This 200-301 question is part of Courseiva's 1,389-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 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 200-301 exam.