What does the "show ipv6 neighbor" command display?

The "show ipv6 neighbor" command is used in networking to display the IPv6 neighbor cache, which includes information about all nearby IPv6 devices and their link-layer addresses. This cache is part of the Neighbor Discovery Protocol (NDP) in IPv6, which helps to determine the link-layer address of a neighbor on the same local link.

When examining the output of this command, you will find details such as the IPv6 addresses of directly connected devices along with their corresponding MAC addresses (link-layer addresses). This information is critical for troubleshooting connectivity issues within a local area network, as it shows which devices are reachable on a local link.

In contrast, the other options refer to different aspects of IPv6 networking but do not relate specifically to the output of the "show ipv6 neighbor" command. For instance, displaying all IPv6 addresses in the routing table or all active sessions and connections pertains to routing and session management, while interface configurations would involve specific settings and parameters of an interface rather than a neighbor cache listing.