OpenBSD manual page server

NAME

ndp — control/diagnose IPv6 Neighbor Discovery Protocol (NDP)

SYNOPSIS

DESCRIPTION

The ndp command manipulates the address mapping table used by the Neighbor Discovery Protocol (NDP).

-A wait

Repeat -a (dump NDP entries) every wait seconds.

-a

Dump the currently existing NDP entries. The following information will be printed:

Neighbor

The IPv6 address of the neighbor.

Linklayer Address

The linklayer address of the neighbor. If the address is not available, it will be displayed as “(incomplete)”.

Netif

The network interface associated with the neighbor cache entry.

Expire

The time until expiry of the entry. If the entry is marked “permanent”, it will never expire.

S

The state of the neighbor cache entry, as a single letter:

D

Delay

I

Incomplete

N

Nostate

P

Probe

R

Reachable

S

Stale

W

Waitdelete

?

Unknown state (should never happen).

Flags

Flags on the neighbor cache entry, in a single letter. They are: local (‘l’), Router (‘R’) and proxy neighbor advertisement (‘p’). This field may be followed by a decimal number, representing the number of NS probes the node has sent during the current state.

-c

Erase all the NDP entries.

-d hostname

Delete the specified NDP entry.

-f filename

Parse entries from file to be inserted in the neighbor cache. See the -s option for a description of the file format.

-i interface

View ND information for the specified interface.

-n

Do not perform domain name resolution. If a name cannot be resolved without DNS, an error will be reported.

-s nodename ether_addr [temp] [proxy]

Register an NDP entry for the node called nodename with the Ether address ether_addr. The Ethernet address is given as six hexadecimal bytes separated by colons. The entry will be permanent unless the word temp is given in the command. If the word proxy is given, this system will act as an ND Proxy server, responding to requests for nodename even though the node address is not its own.

-t

Print a timestamp on each entry, making it possible to merge output with tcpdump(8). Most useful when used with -A.

-V rdomain

Select the routing domain.

EXIT STATUS

The ndp utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

ip6(4), sysctl.conf(5), arp(8), sysctl(8), tcpdump(8)

HISTORY

The ndp command first appeared in the WIDE Hydrangea IPv6 protocol stack kit.