ndp Command

Purpose

IPv6 neighbor discovery display and control.

Syntax

ndp [ -n ] hostname

ndp [ -n ] -a

ndp [ -d ] hostname | IpAddress

ndp [ -i interface_index ] -s hostname addr [ temp ]

Description

The ndp program displays and modifies the IPv6-to-Ethernet, IPv6-to-TokenRing, or IPv6-to-InfiniBand address translation tables used by the IPv6 neighbor discovery protocol.

With no flags, the program displays the current ndp entry for hostname. The host may be specified by name or by number, using IPv6 textual notation.

Flags

Item	Description
- a	Displays all of the current ndp entries.
- d	Lets a super-user delete an entry for the host called hostname with the -d flag.
- i interface_index	Specifies the index of the interface to use when an ndp entry is added with the -s flag (useful with the local-link interface).
- n	Shows network addresses as numbers (normally ndp attempts to display addresses symbolically).
- s hostname addr	Creates an ndp entry for hostname with the Hardware address addr. The Hardware address is given as six hex bytes separated by colons. The entry is permanent unless the temp is specified in the command.

Examples

This is an example output from the - a flag:

# ndp -a
e-crankv6 (::903:9182) at link#2 0:20:af:db:b8:cf
e-crankv6-11 (fe80:0:100::20:afdb:b8cf) at link#2 0:20:af:db:b8:cf
e-crankv6-11 (fe80::2:c903:1:1e85) at link#5 SQP:0xe SLID0x49 DQP:0x48 DLID:0xf 
0:48:fe80::2:c903:1:1e85 [InfiniBand]
# ndp -d e-crankv6-11
e-crankv6-11 (fe80:0:100::20:afdb:b8cf) deleted
# ndp -d fe80::2:c903:1:1e85