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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 utility 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
			 expire.

	     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.

     -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 white spaces
	     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.
	     prefer_source
		     Prefer addresses on the interface as candidates of the
		     source address for outgoing packets.  The default value
		     of this flag is off.  For more details about the entire
		     algorithm of source address selection, see the
		     IMPLEMENTATION file supplied with the KAME kit.

     -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 an NDP entry for a node.	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 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.

DIAGNOSTICS

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

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