What is the purpose of a link-local IPv6 address?

The purpose of a link-local IPv6 address is to provide an address that is only valid on a specific local link. Link-local addresses are automatically configured on all IPv6-enabled interfaces and are used for communication between nodes on the same local network segment. They start with the prefix "FE80::/10" and are not routable, meaning that they cannot be used for communication beyond the local link. This functionality is essential for various network operations, such as neighbor discovery, which allows devices to find each other on the same network, ensuring efficient local communications without requiring globally unique addresses.

By design, link-local addresses help to simplify network configurations, particularly in situations where devices need to communicate directly without the overhead of router-based addressing schemes. This local addressing is crucial for dynamic protocols and services that operate within the confines of a single broadcast domain.