.\"	$OpenBSD: ndp.8,v 1.8 2000/06/20 21:53:43 itojun Exp $
.\"	$KAME: ndp.8,v 1.12 2000/06/20 21:50:17 itojun Exp $
.\"
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.Dd May 17, 1998
.Dt NDP 8
.Os
.\"
.Sh NAME
.Nm ndp
.Nd control/diagnose IPv6 neighbor discovery protocol
.\"
.Sh SYNOPSIS
.Nm ndp
.Fl a
.Op Fl ntl
.Nm ndp
.Fl A Ar wait
.Op Fl ntl
.Nm ndp
.Fl c
.Op Fl nt
.Nm ndp
.Fl d
.Op Fl nt
.Ar hostname
.Nm ndp
.Fl f
.Op Fl nt
.Ar filename
.Nm ndp
.Fl H
.Nm ndp
.Fl I
.Op delete \(ba Ar interface
.Nm ndp
.Fl i
.Ar interface
.Op Ar flags...
.Nm ndp
.Fl p
.Nm ndp
.Fl P
.Nm ndp
.Fl r
.Nm ndp
.Fl R
.Nm ndp
.Fl s
.Op Fl nt
.Ar nodename
.Ar ether_addr
.Op Li temp
.Op Li proxy
.\"
.Sh DESCRIPTION
The
.Nm
command manipulates the address mapping table
used by Neighbor Discovery Protocol (NDP).
.Bl -tag -width Ds
.It Fl a
Dump the currently existing NDP entries.
.It Fl A Ar wait
Repeat
.Fl a
.Pq dump NDP entries
every
.Ar wait
seconds.
.It Fl c
Erase all the NDP entries.
.It Fl d
Delete specified NDP entry.
.It Fl f
Parse the file specified by
.Ar filename .
.It Fl H
Harmonize consistency between the routing table and the default router
list; install the top entry of the list into the kernel routing table.
.It Fl I Op delete \(ba Ar interface
Shows or specifies the default interface used as the default route when
there is no default router. If no argument is given to the option,
the current default interface will be shown.
If an
.Ar interface
is specified, the interface will be used as the default.
If a special keyword
.Ic delete
is specified, the current default interface will be deleted from the kernel.
.It Fl i Ar interface Op Ar flags...
View ND information for the specified interface.
If additional arguments
.Ar flags
are given,
.Nm
sets or clears the specified flags for the interface.
Possible flags are as follows. All of the flags can begin with the
special character
.Ql - ,
which means the flag should be cleared.
.\"
.Bl -tag -width Ds -compact
.It Xo
.Ic nud
.Xc
turn on or off NUD (Neighbor Unreachability Detection) on the
interface. NUD is usually turned on by default.
.El
.It Fl l
Do not truncate numeric IPv6 address.
.It Fl n
Do not try to resolve numeric address to hostname.
.It Fl p
Show prefix list.
.It Fl P
Flush all the entries in the prefix list.
.It Fl r
Show default router list.
.It Fl R
Flush all the entries in the default router list.
.It Fl s
Register a NDP entry for a node.
The entry will be permanent unless the word
.Li temp
is given in the command.
If the word
.Li proxy
is given, this system will act as an proxy NDP server,
responding to requests for
.Ar hostname
even though the host address is not its own.
.It Fl t
Print timestamp on each entries,
to make it possible to merge output with
.Xr tcpdump 1 .
Most useful when used with
.Fl A .
.El
.\"
.Sh RETURN VALUES
The
.Nm
command will exit with 0 on success, and non-zero on errors.
.\"
.Sh SEE ALSO
.Xr arp 8
.\"
.Sh HISTORY
The
.Nm
command first appeared in WIDE Hydrangea IPv6 protocol stack kit.
.\"
.\" .Sh BUGS
.\" (to be written)