ndp - control/diagnose IPv6 neighbor discovery protocol
ndp [-nt] hostname
ndp [-nt] -a | -c | -p
ndp [-nt] -r
ndp [-nt] -H | -P | -R
ndp [-nt] -A wait
ndp [-nt] -d hostname
ndp [-nt] -f filename
ndp [-nt] -i interface [flags ...]
ndp [-nt] -I [interface | delete]
ndp [-nt] -s nodename etheraddr [temp] [proxy]
The ndp command manipulates the address mapping table used
by the Neighbor
Discovery Protocol (NDP).
-a Dump the currently existing NDP entries. The following information
will be printed:
Neighbor IPv6 address of the neighbor.
Linklayer address of the neighbor. It
``(incomplete)'' when the address is not
Netif Network interface associated with the
Expire The time until expiry of the entry. The
become ``permanent'', in which case it
will never expire.
S State of the neighbor cache entry, as a
? Unknown state (should never happen).
Flags Flags on the neighbor cache entry, in a
They are: Router, proxy neighbor
(``p''). The field could be followed by
number, which means the number of NS
probes the node
has sent during the current state.
Repeat -a (dump NDP entries) every wait seconds.
-c Erase all the NDP entries.
-d Delete specified NDP entry.
-f Parse the file specified by filename.
-H Harmonize consistency between the routing table and
router list; install the top entry of the list into
-I Shows the default interface used as the default
route when there
is no default router.
Specifies the default interface used as the default
there is no default router. The interface will be
used as the
The current default interface will be deleted from
-i interface [flags ...]
View ND information for the specified interface. If
arguments flags are given, ndp sets or clears the
for the interface. Each flag should be separated by
or tab characters. Possible flags are as follows.
All of the
flags can begin with the special character `-',
which means the
flag should be cleared. Note that you need -- before -foo in
nud Turn on or off NUD (Neighbor Unreachability
the interface. NUD is usually turned on by
Specify whether or not to accept Router Advertisement
messages received on the interface. Note
that the kernel
does not accept Router Advertisement messages unless the
net.inet6.ip6.accept_rtadv variable is
non-0, even if the
flag is on. This flag is set to 1 by default.
-n Do not try to resolve numeric addresses to hostnames.
-p Show prefix list.
-P Flush all the entries in the prefix list.
-r Show default router list.
-R Flush all the entries in the default router list.
-s Register a NDP entry for a node. The entry will be
the word temp is given in the command. If the
word proxy is
given, this system will act as a proxy NDP server,
requests for hostname even though the host address
is not its
-t Print timestamp on each entry, making it possible to
with tcpdump(8). Most useful when used with -A.
The ndp command exits with 0 on success, and non-zero on errors.
The ndp command first appeared in the WIDE Hydrangea IPv6
OpenBSD 3.6 May 17, 1998
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