NDP(8)							    BSD 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 [expressions ...]
     ndp [-nt] -I [interface | delete]
     ndp [-nt] -s nodename etheraddr [temp] [proxy]

DESCRIPTION

     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
			 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 letter:

			 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 letter.  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 rout-
	     ing table.

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

     -I interface
	     Specifies the default interface to be used when there is no interface specified even though required.

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

     -i interface [expressions ...]
	     View ND information for the specified interface.  If additional arguments expressions are given, ndp sets or clears the flags or
	     variables for the interface as specified in the expression.  Each expression should be separated by white spaces or tab characters.
	     Possible expressions are as follows.  Some of the expressions can begin with the special character '-', which means the flag speci-
	     fied in the expression 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, even if the flag accept_rtadv is on, unless either the net.inet6.ip6.accept_rtadv vari-
		     able is non-0, or the flag override_rtadv is on.  This flag is set to 1 by default.
	     override_rtadv
		     Specify whether or not to override the net.inet6.ip6.accept_rtadv variable.  If the flag is on, then it will suffice to set
		     the flag accept_rtadv to make the kernel accept Router Advertisement messages on the interface.  This flag is set to 0 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.
	     disabled
		     Disable IPv6 operation on the interface.  When disabled, the interface discards any IPv6 packets received on or being sent to
		     the interface.  In the sending case, an error of ENETDOWN will be returned to the application.  This flag is typically set
		     automatically in the kernel as a result of a certain failure of Duplicate Address Detection.  While the flag can be set or
		     cleared by hand with the ndp command, it is not generally advisable to modify this flag manually.
	     basereachable=(number)
		     Specify the BaseReachbleTimer on the interface in millisecond.
	     retrans=(number)
		     Specify the RetransTimer on the interface in millisecond.
	     curhlim=(number)
		     Specify the Cur Hop Limit on the interface.

     -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.

RETURN VALUES

     The ndp command will exit 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.

BSD
								 November 6, 2009							       BSD