IP blocks are the main container in the IP address space. You must create at least one IPv6 block within a configuration to be able to add networks and IP addresses. You can add blocks to the Global ID block in the Unique Local Address Space and to the Global Routing Prefix block in the Global Unicast Address Space. A network is a group of IP addresses that can be routed. A network must be contained within an IP block.
Note: The Add IPv6 Block page displays different fields when you are working with blocks in the Unique Local Address Space and Global Unicast Address Space.