1.\" Copyright (c) 1985, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)arp.8 8.1 (Berkeley) 6/6/93 33.\" $FreeBSD: src/usr.sbin/arp/arp.8,v 1.8.2.11 2003/03/11 21:13:48 trhodes Exp $ 34.\" $DragonFly: src/usr.sbin/arp/arp.8,v 1.3 2006/01/19 22:19:31 dillon Exp $ 35.\" 36.Dd June 6, 1993 37.Dt ARP 8 38.Os 39.Sh NAME 40.Nm arp 41.Nd address resolution display and control 42.Sh SYNOPSIS 43.Nm 44.Op Fl n 45.Op Fl c Ar cpu 46.Ar hostname 47.Nm 48.Op Fl n 49.Op Fl c Ar cpu 50.Fl a 51.Nm 52.Fl d Ar hostname 53.Op Cm pub 54.Nm 55.Fl d 56.Fl a 57.Nm 58.Fl s Ar hostname ether_addr 59.Op Cm temp 60.Op Cm pub Op Cm only 61.Nm 62.Fl S Ar hostname ether_addr 63.Op Cm temp 64.Op Cm pub Op Cm only 65.Nm 66.Fl f Ar filename 67.Sh DESCRIPTION 68The 69.Nm 70utility displays and modifies the Internet-to-Ethernet address translation 71tables used by the address resolution protocol 72.Pq Xr arp 4 . 73With no flags, the program displays the current 74.Tn ARP 75entry for 76.Ar hostname . 77The host may be specified by name or by number, 78using Internet dot notation. 79.Pp 80Available options: 81.Bl -tag -width indent 82.It Fl a 83The program displays or deletes all of the current 84.Tn ARP 85entries. 86.It Fl c Ar cpu 87On SMP systems the route table is replicated. This option allows 88the route table for a specific cpu to be accessed and exists 89primarily for debugging purposes. 90.It Fl d 91A super-user may delete an entry for the host called 92.Ar hostname 93with the 94.Fl d 95flag. 96If the 97.Cm pub 98keyword is specified, only the 99.Dq published 100.Tn ARP 101entry 102for this host will be deleted. 103.Pp 104Alternatively, the 105.Fl d 106flag may be combined with the 107.Fl a 108flag to delete all entries. 109.It Fl n 110Show network addresses as numbers (normally 111.Nm 112attempts to display addresses symbolically). 113.It Fl s Ar hostname ether_addr 114Create an 115.Tn ARP 116entry for the host called 117.Ar hostname 118with the Ethernet address 119.Ar ether_addr . 120The Ethernet address is given as six hex bytes separated by colons. 121The entry will be permanent unless the word 122.Cm temp 123is given in the command. 124If the word 125.Cm pub 126is given, the entry will be 127.Dq published ; 128i.e., this system will 129act as an 130.Tn ARP 131server, 132responding to requests for 133.Ar hostname 134even though the host address is not its own. 135In this case the 136.Ar ether_addr 137can be given as 138.Cm auto 139in which case the interfaces on this host will be examined, 140and if one of them is found to occupy the same subnet, its 141Ethernet address will be used. 142If the 143.Cm only 144keyword is also specified, this will create a 145.Dq "published (proxy only)" 146entry. 147This type of entry is created automatically if 148.Nm 149detects that a routing table entry for 150.Ar hostname 151already exists. 152.It Fl S Ar hostname ether_addr 153Is just like 154.Fl s 155except any existing 156.Tn ARP 157entry for this host will be deleted first. 158.It Fl f Ar filename 159Cause the file 160.Ar filename 161to be read and multiple entries to be set in the 162.Tn ARP 163tables. Entries 164in the file should be of the form 165.Pp 166.Bd -ragged -offset indent -compact 167.Ar hostname ether_addr 168.Op Cm temp 169.Op Cm pub 170.Ed 171.Pp 172with argument meanings as given above. 173Leading whitespace and empty lines are ignored. 174A 175.Ql # 176character will mark the rest of the line as a comment. 177.El 178.Sh SEE ALSO 179.Xr inet 3 , 180.Xr arp 4 , 181.Xr ifconfig 8 182.Sh HISTORY 183The 184.Nm 185utility appeared in 186.Bx 4.3 . 187