Which address prefix does OSPFv3 use when multiple IPv6 addresses are configured on a single interface?
OSPFv3 (Open Shortest Path First version 3) is a routing protocol that is used for IPv6 networks. When multiple IPv6 addresses are configured on a single interface, OSPFv3 uses the link-local address for its routing process.
The link-local address is automatically generated by the interface and is used for communication within the local network segment. OSPFv3 uses this address as the source and destination address for OSPFv3 messages sent over the network.
Therefore, the answer to the question is not any of the options provided: OSPFv3 uses the link-local address, which is not the lowest, highest, or any specific prefix configured on the interface.
It's worth noting that while OSPFv3 uses the link-local address for its routing process, it can also be configured to use other IPv6 addresses on the interface, such as a global unicast address, as the OSPFv3 router ID. However, this is not the same as the prefix used for routing purposes.