In IPv6, what is the purpose of link-local addresses and what prefix do they typically begin with?

In IPv6, what is the purpose of link-local addresses and what prefix do they typically begin with?

• A. Link-local addresses are globally routable on the internet.
• B. They are used as global addresses.
• C. They are reserved for multicast only.
• D. Link-local addresses enable communication within a single link; they begin with FE80::/10.

Answer: (D)

Link-local addresses provide a way for devices on the same physical or logical link to communicate without needing routing to other networks. They’re used for essential local operations like neighbor discovery and automatic address configuration, so a host can talk to others on the same link even before any global routes are established. Because their scope is just the local link, routers won’t forward these packets to other networks. The prefix for these addresses is FE80::/10, meaning any address from FE80:: up to FEBF:: is considered link-local. The rest of the address includes the interface identifier unique to the device. This combination ensures every device on a link can use a locally-scoped address to communicate and perform startup and maintenance tasks, while not being usable for global internet routing.

Link-local addresses provide a way for devices on the same physical or logical link to communicate without needing routing to other networks. They’re used for essential local operations like neighbor discovery and automatic address configuration, so a host can talk to others on the same link even before any global routes are established. Because their scope is just the local link, routers won’t forward these packets to other networks.

The prefix for these addresses is FE80::/10, meaning any address from FE80:: up to FEBF:: is considered link-local. The rest of the address includes the interface identifier unique to the device. This combination ensures every device on a link can use a locally-scoped address to communicate and perform startup and maintenance tasks, while not being usable for global internet routing.