ARP(8)                  OpenBSD System Manager's Manual                 ARP(8)

NAME
     arp - address resolution display and control

SYNOPSIS
     arp [-n] hostname
     arp [-n] -a
     arp -d hostname
     arp -s hostname ether_addr [temp | permanent] [pub]
     arp -f filename

DESCRIPTION
     The arp program displays and modifies the Internet-to-Ethernet address
     translation tables used by the address resolution protocol (arp(4)). With
     no flags, the program displays the current ARP entry for hostname. The
     host may be specified by name or by number, using Internet dot notation.

     Available options:

     -a      The program displays all of the current ARP entries.

     -d      A superuser may delete an entry for the host called hostname with
             the -d flag.

     -n      Show network addresses as numbers (normally arp attempts to dis-
             play addresses symbolically).

     -s hostname ether_addr
             Create an ARP entry for the host called hostname with the Ether-
             net address ether_addr. The Ethernet address is given as six hex
             bytes separated by colons.  The entry will be static, i.e., not
             time out, unless the word temp is given in the command.  A static
             ARP entry can be overwritten by network traffic, unless the word
             permanent is given.  If the word pub is given, the entry will be
             ``published''; i.e., this system will act as an ARP server, re-
             sponding to requests for hostname even though the host address is
             not its own.  This behavior has traditionally been called proxy
             arp.

     -f      Causes the file filename to be read and multiple entries to be
             set in the ARP tables.  Entries in the file should be of the form

                   hostname ether_addr [temp | permanent] [pub]

             with argument meanings as given above.

EXAMPLES
     To view the current arp table:

           arp -a

     To create a permanent entry (One that cannot be overwritten by other net-
     work traffic):

           arp -s 10.0.0.2 00:90:27:bb:cc:dd permanent

     To create proxy arp entries on an interface, fxp0, for the IP Addresses
     204.1.2.3 and 204.1.2.4, do a:

           arp -s 209.1.2.3 00:90:27:bb:cc:dd pub
           arp -s 209.1.2.4 00:90:27:bb:cc:dd pub

     (where 00:90:27:bb:cc:dd is the MAC address of fxp0)

SEE ALSO
     inet(3), arp(4), ifconfig(8)

HISTORY
     The arp command appeared in 4.3BSD.

OpenBSD 2.9                      July 14, 1999                               2
