Service Manual
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Neighbor Discovery Protocol (NDP)
The neighbor discovery protocol for IPv6 is dened in RFC 2461 as part of the Stateless Address Autoconguration protocol. It
replaces the Address Resolution Protocol used with IPv4. NDP denes mechanisms for solving the following problems:
• Router discovery: Hosts can locate routers residing on a link
• Prex discovery: Hosts can discover address prexes for the link
• Parameter discovery
• Address autoconguration — conguration of addresses for an interface
• Address resolution — mapping from IP address to link-layer address
• Next-hop determination
• Neighbor unreachability detection (NUD): Determine that a neighbor is no longer reachable on the link.
• Duplicate address detection (DAD): Allow a node to check whether a proposed address is already in use.
• Redirect: The router can inform a node about a better rst-hop.
NDP uses the following ve ICMPv6 packet types in its implementation:
• Router Solicitation
• Router Advertisement
• Neighbor Solicitation
• Neighbor Advertisement
• Redirect
clear ipv6 neighbors
Delete all entries in the IPv6 neighbor discovery cache or neighbors of a specic interface. Static entries are not removed using this
command.
Syntax
clear ipv6 neighbors [ipv6-address | interface]
Parameters
ipv6-address Enter the IPv6 address of the neighbor in the x:x:x:x::x format to remove a specic
IPv6 neighbor.
NOTE: The :: notation species successive hexadecimal elds of zero.
interface interface To remove all neighbor entries learned on a specic interface, enter the keyword
interface then the interface type and slot/port or number information of the
interface:
• For a 1-Gigabit Ethernet interface, enter the keyword GigabitEthernet
then the slot/port information.
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Neighbor Discovery Protocol (NDP)