arp(8)							      System Manager's Manual							    arp(8)

NAME

       arp - Displays and controls Address Resolution Protocol (ARP) tables

SYNOPSIS

       /usr/sbin/arp [-u] [-n] hostname

       arp -a [-u] [-n] [-i] [system]

       arp -d hostname

       arp -f filename

       arp -g hostname

       arp -s [-u] hostname hardware_addr [temp] [pub] [trail]

FLAGS

       Displays  all  of  the current ARP entries.  Deletes the entry for hostname if the user issuing the command has superuser authority.  Reads
       entries from filename and adds those entries to the ARP tables.	Use of this flag requires superuser privilege.	Entries in the	file  have
       the following format:

	      hostname hardware_addr [temp] [pub] [trail]

	      Fields  in  this	format	are  as follows: Specifies the remote host identified by the entry.  Specifies the hardware address of the
	      remote host.  The address is given as 6 hexadecimal bytes separated by colons.  Specifies that this ARP table  entry  is	temporary.
	      When this argument is not used, the table entry is permanent.  Indicates that the table entry will be published and that the current
	      system will act as an ARP server, responding to requests for hostname even though the host address is not its own.   Indicates  that
	      the  trailer  encapsulation may be sent to this host.  Sends a gratuitous ARP packet.  The hostname can be a local host name, alias,
	      or IP address.  Displays the interface with which the ARP entry is associated.  Displays numeric IP addresses and hardware addresses
	      only.   When this flag is not specified, arp displays hostnames, numeric IP addresses, and hardware addresses.  Creates a single ARP
	      entry for hostname.  Use of this flag requires superuser privilege.  The arguments are explained in the discussion of the  -f  flag.
	      Displays	the  MAC  address in noncanonical form with address bytes reversed and separated by a colon character (:). By default, all
	      addresses are displayed in canonical form with address bytes separated by the hyphen character (-).

	      When used with the -s flag, this indicates that the hardware_addr is in noncanonical form.

DESCRIPTION

       The arp command displays or modifies the current ARP entry for the host specified by hostname.  The host may be specified by name  or  num-
       ber, using Internet dot notation.

       With no flags, the program displays the current ARP entry for hostname.

       The ARP tables can be displayed by any user, but only the superuser can modify them.

EXAMPLES

       To display the ARP address-mapping tables for the local host, enter:

	      arp -a

	      alpha1.dec.com (16.181.20.2) at 08-00-2b-2c-f5-31 alpha2.dec.com (16.100.21.20) at 08-00-2b-3c-2d-fd To display the ARP address-map-
	      ping tables for the local host and the interface, enter:

	      arp -a -i

	      jupiter (192.45.20.2) at 08-00-2b-1a-f8-23 (tu0) sigma (204.126.98.16) at 08-00-2b-5f-1d-33 (tu1) To add	a  single  entry  for  the
	      remote host laszlo to the ARP mapping tables temporarily, enter:

	      arp -s laszlo 08:00:2b:0f:44:23 temp

	      The address is considered canonical even though the bytes are separated by colons. For input, the arp command does not use the colon
	      (:) and hyphen (-) characters to indicate whether the address is canonical or noncanonical.

	      Note that you must have superuser authority to execute this command.  To add a single entry for the remote host laszlo  to  the  ARP
	      mapping tables temporarily, enter:

	      arp -u -s laszlo 10:00:d4:f0:22:c4 temp

	      The -u flag indicates the address is noncanonical. Note that you must have superuser authority to execute this command.  To add mul-
	      tiple entries to the ARP mapping tables from the file newentries, enter:

	      arp -f newentries

	      Note that you must have superuser authority to execute this command.

FILES

       Specifies the command path.

RELATED INFORMATION

       Commands: netstat(1), ifconfig(8)

       Protocols: arp(7)

       Specifications:	RFC 826 delim off

																	    arp(8)