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 . 144Note that the kernel does not accept Router Advertisement messages 145unless the 146.Va net.inet6.ip6.accept_rtadv 147variable is non-0, even if the flag is on. 148This flag is set to 1 by default. 149.It Xo 150.Ic auto_linklocal 151.Xc 152Specify whether or not to perform automatic link-local address 153configuration on the 154.Ar interface . 155This flag is set by the 156.Va net.inet6.ip6.auto_linklocal 157sysctl variable. 158.El 159.It Fl n 160Do not try to resolve numeric address to hostname. 161.It Fl p 162Show prefix list. 163.It Fl P 164Flush all the entries in the prefix list. 165.It Fl r 166Show default router list. 167.It Fl R 168Flush all the entries in the default router list. 169.It Fl s 170Register an NDP entry for a node. 171The entry will be permanent unless the word 172.Li temp 173is given in the command. 174If the word 175.Li proxy 176is given, this system will act as a proxy NDP server, 177responding to requests for 178.Ar hostname 179even though the host address is not its own. 180.It Fl t 181Print timestamp for each entry, 182to make it possible to merge the output with 183.Xr tcpdump 1 . 184Most useful when used with 185.Fl A . 186.El 187.\" 188.Sh EXIT STATUS 189.Ex -std 190.\" 191.Sh SEE ALSO 192.Xr arp 8 193.\" 194.Sh HISTORY 195The 196.Nm 197utility first appeared in WIDE Hydrangea IPv6 protocol stack kit. 198.\" 199.\" .Sh BUGS 200.\" (to be written) 201