Understanding IPv6 Terminology

The following terminology is used to define IPv6 concepts and describe IPv6 features:

• Node An IPv6-enabled network device that includes both hosts and routers.
• Host An IPv6-enabled network device that cannot forward IPv6 packets that are not explicitly addressed to itself. A host is an endpoint for IPv6 communications (either the source or destination) and drops all traffic not explicitly addressed to it.
• Router An IPv6-enabled network device that can forward IPv6 packets that are not explicitly addressed to itself. IPv6 routers also typically advertise their presence to IPv6 hosts on their attached links.
• Link One or more LAN (such as Ethernet) or wide area network (WAN, such as Pointto- Point Protocol [PPP]) network segments bounded by routers. Like interfaces, links may be either physical or logical.
• Neighbors Nodes that are connected to the same physical or logical link.
• Subnet One or more links having the same 64-bit IPv6 address prefix.
• Interface A representation of a node's attachment to a link. This can be a physical interface (such as a network adapter) or a logical interface (such as a tunnel interface).

Note A n IPv6 address identifies an interface, not a node. A node is identified by having one or more unicast IPv6 addresses assigned to one of its interfaces.