TCP/IPv6 Configuration and Management Manual (G06.29+, H06.03+, J06.03+)

IPv6 Fundamentals
HP NonStop TCP/IPv6 Configuration and Management Manual—524523-012
A-14
Neighbor Discovery Protocol
How hosts discover the set of address prefixes that define which destinations are
on-link for an attached link. (Nodes use prefixes to distinguish destinations that
reside on-link from those only reachable through a router.)

Parameter discovery
How a node learns such link parameters as the link MTU or such Internet
parameters as the hop-limit value to place in outgoing packets.

Address autoconfiguration
How nodes automatically configure an address for an interface.

Address resolution
How nodes determine the link-layer address of an on-link destination (a neighbor)
given only the destination's IP address.

Next-hop determination
How mapping an IP destination address into the IP address of the neighbor to
which traffic for the destination should be sent occurs. The next- hop can be a
router or the destination itself.

Neighbor unreachability detection
How nodes determine that a neighbor is no longer reachable. For neighbors used
as routers, alternate default routers can be tried. For both routers and hosts,
address resolution can be performed again.

Duplicate address detection
How a node determines that an address it wishes to use is not already in use by
another node.

Redirect
How a router informs a host of a better first-hop node to reach a particular
destination.
Neighbor discovery defines five ICMP packet types: a pair of router solicitation and
router advertisement messages, a pair of neighbor solicitation and neighbor
advertisements messages, and a redirect message. The messages serve these
purpose:

Router solicitation
When an interface becomes enabled, hosts can send out router solicitations that
request routers to generate router advertisements immediately rather than at the
routers’ next scheduled time.

Router advertisement
Routers advertise their presence together with various link and Internet parameters
either periodically, or in response to a router solicitation message. Router