1.\" $FreeBSD: src/usr.sbin/ndp/ndp.8,v 1.1.2.8 2003/08/12 16:27:57 ume Exp $ 2.\" $KAME: ndp.8,v 1.15 2001/02/08 07:17:03 itojun Exp $ 3.\" 4.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the project nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.Dd March 1, 2024 32.Dt NDP 8 33.Os 34.\" 35.Sh NAME 36.Nm ndp 37.Nd control/diagnose IPv6 neighbor discovery protocol 38.\" 39.Sh SYNOPSIS 40.Nm 41.Fl a 42.Op Fl nt 43.Nm 44.Fl A Ar wait 45.Op Fl nt 46.Nm 47.Fl c 48.Op Fl nt 49.Nm 50.Fl d 51.Op Fl nt 52.Ar hostname 53.Nm 54.Fl f 55.Op Fl nt 56.Ar filename 57.Nm 58.Fl H 59.Nm 60.Fl I 61.Op Cm delete | Ar interface 62.Nm 63.Fl i 64.Ar interface 65.Op Ar flags... 66.Nm 67.Fl p 68.Nm 69.Fl P 70.Nm 71.Fl r 72.Nm 73.Fl R 74.Nm 75.Fl s 76.Op Fl nt 77.Ar nodename 78.Ar ether_addr 79.Op Li temp 80.Op Li proxy 81.\" 82.Sh DESCRIPTION 83The 84.Nm 85utility manipulates the address mapping table 86used by Neighbor Discovery Protocol (NDP). 87.Bl -tag -width Ds 88.It Fl a 89Dump the currently existing NDP entries. 90.It Fl A Ar wait 91Repeat 92.Fl a 93(dump NDP entries) 94every 95.Ar wait 96seconds. 97.It Fl c 98Erase all the NDP entries. 99.It Fl d 100Delete specified NDP entry. 101.It Fl f 102Parse the file specified by 103.Ar filename . 104.It Fl H 105Harmonize consistency between the routing table and the default router 106list; install the top entry of the list into the kernel routing table. 107.It Fl I Op Cm delete | Ar interface 108Shows or specifies the default interface used as the default route when 109there is no default router. 110If no argument is given to the option, 111the current default interface will be shown. 112If an 113.Ar interface 114is specified, the interface will be used as the default. 115If a special keyword 116.Ic delete 117is specified, the current default interface will be deleted from the kernel. 118.It Fl i Ar interface Op Ar flags... 119View ND information for the specified interface. 120If additional arguments 121.Ar flags 122are given, 123.Nm 124sets or clears the specified flags for the interface. 125Possible flags are as follows. 126All of the flags can begin with the 127special character 128.Ql - , 129which means the flag should be cleared. 130.\" 131.Bl -tag -width Ds -compact 132.It Xo 133.Ic nud 134.Xc 135turn on or off NUD (Neighbor Unreachability Detection) on the 136interface. 137NUD is usually turned on by default. 138.It Xo 139.Ic accept_rtadv 140.Xc 141Specify whether or not to accept Router Advertisement messages 142received on the 143.Ar interface . 144This flag is set by the 145.Va net.inet6.ip6.accept_rtadv 146sysctl variable. 147.It Xo 148.Ic auto_linklocal 149.Xc 150Specify whether or not to perform automatic link-local address 151configuration on the 152.Ar interface . 153This flag is set by the 154.Va net.inet6.ip6.auto_linklocal 155sysctl variable. 156.El 157.It Fl n 158Do not try to resolve numeric address to hostname. 159.It Fl p 160Show prefix list. 161.It Fl P 162Flush all the entries in the prefix list. 163.It Fl r 164Show default router list. 165.It Fl R 166Flush all the entries in the default router list. 167.It Fl s 168Register an NDP entry for a node. 169The entry will be permanent unless the word 170.Li temp 171is given in the command. 172If the word 173.Li proxy 174is given, this system will act as a proxy NDP server, 175responding to requests for 176.Ar hostname 177even though the host address is not its own. 178.It Fl t 179Print timestamp for each entry, 180to make it possible to merge the output with 181.Xr tcpdump 1 . 182Most useful when used with 183.Fl A . 184.El 185.\" 186.Sh EXIT STATUS 187.Ex -std 188.\" 189.Sh SEE ALSO 190.Xr arp 8 191.\" 192.Sh HISTORY 193The 194.Nm 195utility first appeared in WIDE Hydrangea IPv6 protocol stack kit. 196.\" 197.\" .Sh BUGS 198.\" (to be written) 199