NDP(8)                  OpenBSD System Manager's Manual                 NDP(8)

NAME
     ndp - control/diagnose IPv6 neighbor discovery protocol

SYNOPSIS
     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]

DESCRIPTION
     The ndp command manipulates the address mapping table used by the Neigh-
     bor Discovery Protocol (NDP).

     -a      Dump the currently existing NDP entries.  The following informa-
             tion will be printed:

             Neighbor    IPv6 address of the neighbor.

             Linklayer Address
                         Linklayer address of the neighbor.  It could be
                         ``(incomplete)'' when the address is not available.

             Netif       Network interface associated with the neighbor cache
                         entry.

             Expire      The time until expiry of the entry.  The entry could
                         become ``permanent'', in which case it will never ex-
                         pire.

             S           State of the neighbor cache entry, as a single let-
                         ter:

                         N       Nostate
                         W       Waitdelete
                         I       Incomplete
                         R       Reachable
                         S       Stale
                         D       Delay
                         P       Probe
                         ?       Unknown state (should never happen).

             Flags       Flags on the neighbor cache entry, in a single let-
                         ter.  They are: Router, proxy neighbor advertisement
                         (``p'').  The field could be followed by a decimal
                         number, which means the number of NS probes the node
                         has sent during the current state.

     -A wait
             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 the default
             router list; install the top entry of the list into the kernel
             routing table.

     -I      Shows the default interface used as the default route when there
             is no default router.

     -I interface
             Specifies the default interface used as the default route when
             there is no default router.  The interface will be used as the
             default.

     -I delete
             The current default interface will be deleted from the kernel.

     -i interface [flags ...]
             View ND information for the specified interface.  If additional
             arguments flags are given, ndp sets or clears the specified flags
             for the interface.  Each flag should be separated by whitespace
             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
             this case.

             nud     Turn on or off NUD (Neighbor Unreachability Detection) on
                     the interface.  NUD is usually turned on by default.
             accept_rtadv
                     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 permanent un-
             less the word temp is given in the command.  If the word proxy is
             given, this system will act as a proxy NDP server, responding to
             requests for hostname even though the host address is not its
             own.

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

RETURN VALUES
     The ndp command exits with 0 on success, and non-zero on errors.

SEE ALSO
     arp(8)

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

OpenBSD 3.5                      May 17, 1998                                2
