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.

• ✗

  Unique local

  Why it's wrong here

  Unique local addresses (FC00::/7, with FD00::/8 for locally assigned IDs) are the IPv6 analog of RFC 1918 private IPv4 addresses, intended for internal networks and not routable on the global Internet. They are not generated automatically by the interface itself; they must be manually configured, assigned via DHCPv6, or statically defined by an administrator. Their scope can span multiple subnets within an organization, unlike the single-link scope of link-local, which is why they are not the auto-created interface type this question is asking about.

  When this WOULD be correct

  If the exam question asked for an IPv6 address type that is used for private communication within a specific organization or site, without the need for global routing, then 'Unique local' would be the correct answer.

• ✗

  Global unicast

  Why it's wrong here

  Global unicast addresses (2000::/3) are routable on the public IPv6 Internet and must be derived from a global routing prefix obtained from an ISP or regional registry. They are not automatically created on an interface unless a router advertises a prefix via Router Advertisement (SLAAC) or the host receives an assignment via DHCPv6. In the absence of any configured prefix or advertisement, the interface still has only its link-local address, so global unicast is not an automatically generated default address type.

  When this WOULD be correct

  If the question asked which IPv6 address type is used for communication over the internet and is routable globally, then 'Global unicast' would be the correct answer. This scenario would focus on addressing types suitable for broader network communication rather than local-link.

• ✓

  Link-local

  Why this is correct

  Link-local IPv6 addresses are automatically created on every IPv6-enabled interface without any manual configuration or stateful protocol. They use the FE80::/10 prefix and are derived from the interface's MAC address (or a privacy-generated value) using EUI-64 or RFC 7217. Their scope is strictly the local link, enabling Neighbor Discovery Protocol, address resolution, and router discovery even before any other global address is present. Because they are always present, they are the correct answer to which IPv6 address type is auto-created.

• ✗

  Anycast

  Why it's wrong here

  Anycast is not a separate address type but a delivery model where a single unicast address (often a global unicast or unique local address) is assigned to multiple interfaces, and routers forward packets to the nearest interface by routing metric. It is never automatically created on an interface and requires explicit network-wide configuration and routing protocol support. Because anycast addresses are indistinguishable from unicast addresses from the sending host's perspective, they cannot be the interface's self-generated link-local address, making this option incorrect.

  When this WOULD be correct

  If the question were to ask about the address type that allows for communication with the nearest instance of a service, such as a DNS server, in a multi-homed environment, then 'Anycast' would be the correct answer. This scenario would focus on routing and service discovery rather than local-link communication.

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?”

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