Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
ARP(8)			FreeBSD	System Manager's Manual			ARP(8)

     arp -- address resolution display and control

     arp [--libxo options] [-n]	[-i interface] hostname
     arp [--libxo options] [-n]	[-i interface] -a
     arp -d hostname [pub]
     arp -d [-i	interface] -a
     arp -s hostname ether_addr	[temp] [blackhole | reject] [pub]
     arp -S hostname ether_addr	[temp] [blackhole | reject] [pub]
     arp -f filename

     The arp utility 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	nota-

     Available options:

	     Generate output via libxo(3) in a selection of different human
	     and machine readable formats.  See	xo_parse_args(3) for details
	     on	command	line arguments.

     -a	     The program displays or, if it is used with the -d	flag, deletes
	     all of the	current	ARP entries.

     -d	     A super-user may delete an	entry for the host called hostname
	     with the -d flag.	If the pub keyword is specified, only the
	     "published" ARP entry for this host will be deleted.

	     Alternatively, the	-d flag	may be combined	with the -a flag to
	     delete all	entries.

     -i	interface
	     Limit the operation scope to the ARP entries on interface.	 Ap-
	     plicable only to the following operations:	display	one, display
	     all, delete all.

     -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 permanent unless
	     the word temp is given in the command.  If	the word pub is	given,
	     the entry will be "published"; i.e., this system will act as an
	     ARP server, responding to requests	for hostname even though the
	     host address is not its own.  In this case	the ether_addr can be
	     given as auto in which case the interfaces	on this	host will be
	     examined, and if one of them is found to occupy the same subnet,
	     its Ethernet address will be used.

	     If	the reject keyword is specified	the entry will be marked so
	     that traffic to the host will be discarded	and the	sender will be
	     notified the host is unreachable.	The blackhole keyword is simi-
	     lar in that traffic is discarded but the sender is	not notified.
	     These can be used to block	external traffic to a host without us-
	     ing a firewall.

     -S	hostname ether_addr
	     Is	just like -s except any	existing ARP entry for this host will
	     be	deleted	first.

     -f	filename
	     Cause 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] [blackhole | reject] [pub]

	     with argument meanings as given above.  Leading whitespace	and
	     empty lines are ignored.  A `#' character will mark the rest of
	     the line as a comment.

     inet(3), libxo(3),	xo_parse_args(3), arp(4), ifconfig(8), ndp(8)

     The arp utility appeared in 4.3BSD.

FreeBSD	13.0			 July 13, 2020			  FreeBSD 13.0


Want to link to this manual page? Use this URL:

home | help