CCNA Network Infrastructure and Connectivity Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  IPv6 hosts commonly use the router’s link-local address as the next hop on the local segment.

  Why this is correct

  In IPv6, routers send Router Advertisements (RAs) on the local link with their link-local address as the source and as the advertised next-hop address. Hosts install a default route (::/0) pointing to that link-local address, which is reachable on the same link. This is standard operation; global unicast addresses are not required—or even preferred—for next-hop determination.

• ✗

  The host has learned the wrong default route because IPv6 gateways must always be global unicast.

  Why it's wrong here

  The assertion that IPv6 gateways must always be global unicast is incorrect. The Neighbor Discovery Protocol (NDP) defines that Router Advertisements carry the router's link-local address, and hosts use that link-local address for the default route, even for off-link traffic. A global unicast address is not needed as a gateway; it is merely one of the router's other configured addresses.

  When this WOULD be correct

  In a scenario where a question states that an IPv6 host is configured to only communicate with other devices on the same local link and does not require global connectivity, the statement that 'IPv6 gateways must always be global unicast' could be correct. This would imply a misunderstanding of link-local addressing in a strictly local context.

• ✗

  The host can reach only local destinations when the next hop is link-local.

  Why it's wrong here

  Having a link-local next hop does not confine the host to local destinations. When the host sends a packet to an off-link address, it frames the packet to the router's link-local address at Layer 2, and the router then forwards it out the appropriate interface. The link-local address is only the local delivery target; reachability beyond the link is handled by the router's forwarding decision.

  When this WOULD be correct

  In a scenario where a question specifies that the host is configured to communicate only within a local network and does not have a global unicast address, stating that a link-local next hop limits communication to local destinations would be accurate.

• ✗

  The router advertisement has failed because it did not provide a MAC address.

  Why it's wrong here

  This misunderstands the RA process: an RA does not fail for omitting a MAC address because a router can be discovered purely by its link-local source address, and the interface's MAC address can be obtained via Neighbor Solicitation/Advertisement (NDP) or an optional Source Link-Layer Address option in the RA. The described scenario is not an RA failure; it is simply normal IPv6 behavior in which the next hop is link-local.

  When this WOULD be correct

  In a question where the context specifies that router advertisements are expected to include MAC addresses for proper routing functionality, option D could be correct if the absence of a MAC address leads to a failure in establishing a valid next-hop address.

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.

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?”