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.

• ✗

  FC00::/7

  Why it's wrong here

  The FC00::/7 prefix defines IPv6 Unique Local Addresses (ULAs), which are intended for local communications within a site or private network and are routable within that administrative domain. Unlike link-local addresses, ULAs include a 40-bit global ID and a 16-bit subnet ID, making them routable across routers within the site, though they are not globally reachable on the public internet. Link-local addresses, signified by FE80::/10, are automatically configured on every interface, are never forwarded by routers, and lack any routing or site-level scope.

  When this WOULD be correct

  If the exam question asked for the prefix used for Unique Local Addresses in IPv6, then FC00::/7 would be the correct answer. For example, a question could specify the type of address used for private communication within a site.

• ✓

  FE80::/10

  Why this is correct

  IPv6 link-local addresses are uniquely identified by the FE80::/10 prefix, which is reserved for communication solely within a single network segment. This specific prefix ensures that packets with these source or destination addresses never traverse a router, satisfying the constraint of being confined to the local link. Every IPv6-enabled interface automatically configures a link-local address from this range, enabling essential neighbour discovery and stateless address autoconfiguration processes.

• ✗

  2000::/3

  Why it's wrong here

  The 2000::/3 prefix covers all IPv6 Global Unicast Addresses (GUAs), which are allocated by RIRs and designed to be globally routable across the public internet. These addresses have a hierarchical structure with a global routing prefix, subnet ID, and interface ID, and they must be unique worldwide to enable end-to-end routing. Link-local addresses, on the other hand, operate only on the local physical link, are automatically derived from the interface's MAC address or other mechanisms, and are strictly non-routable, so they fall outside the global unicast space.

  When this WOULD be correct

  If the question asked for the prefix used for global unicast addresses in IPv6, option C would be correct, as it identifies the range of addresses that are routable on the internet.

• ✗

  FF00::/8

  Why it's wrong here

  The FF00::/8 prefix is reserved exclusively for IPv6 multicast addressing, which is used to transmit a packet to multiple interfaces that have joined a multicast group. Multicast addresses function at the network layer for one-to-many delivery, whereas link-local addresses are unicast addresses that identify a single interface specifically within a single network segment. Furthermore, multicast addresses incorporate a 4-bit scope field (e.g., FF02::/16 for link-local scope), but they are categorically distinct from the unicast link-local prefix FE80::/10.

  When this WOULD be correct

  If the question asked about the prefix used for multicast addresses in IPv6, then D would be the correct answer. For example, a question could state, 'Which IPv6 prefix is designated for multicast 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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