Cisco Certified Network Associate (CCNA) Practice Exam

What does an IPv6 address starting with FE80 indicate?

1. Global Unicast

2. Loopback

3. Link-Local Unicast

4. Multicast

The correct answer is: Link-Local Unicast

An IPv6 address that begins with FE80 is designated as a Link-Local Unicast address. Link-Local addresses are used for communication between nodes on the same local link or network segment and are not routable beyond that link. They are automatically configured on all IPv6-enabled interfaces and play a critical role in local communication such as neighbor discovery and automatic address configuration. Each Link-Local address begins with the prefix FE80 and is followed by a series of zero bits (0s), which can be represented in various shorthand forms. Devices use these addresses for operations such as address auto-configuration and discovering other devices on the same local link without requiring a globally routable address. It's essential to note that Link-Local addresses only work within the local network segment, and packets sent to these addresses cannot be routed to other links or networks. The other options represent different types of addresses. Global Unicast addresses are used for identification and communication over the global Internet, while the Loopback address is an address (usually ::1 for IPv6) used to send packets back to the same device. Multicast addresses are used for one-to-many communication over a network, allowing a single packet to be sent to multiple destinations.