home | help 
NDP(8)			     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 utility 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 en-
		       try.

	     Expire    The time until expiry of the entry.  The entry could  be-
		       come "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
	     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  de-
	     fault.

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

     -i interface [expressions ...]
	     View ND information for the specified interface.  If additional ar-
	     guments  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  mes-
		     sages 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 algo-
		     rithm 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  be-
		     ing  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 com-
		     mand, it is not generally advisable  to  modify  this  flag
		     manually.

	     basereachable=(number)
		     Specify the BaseReachbleTimer on the interface in millisec-
		     ond.

	     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 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(1).  Most useful when used with -A.

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

SEE ALSO
     arp(8)

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

FreeBSD 8.1			  May 17, 1998				  NDP(8)
home | help