ARP(8) BSD System Manager's Manual ARP(8)NAMEarp - address resolution display and control
SYNOPSISarp [-n] hostname
arp [-n] -a
arp-d hostname
arp-d -a
arp [-F] -s hostname ether_addr [temp | permanent] [pub]
arp [-F] -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 Display all of the current ARP entries. See also the -d option
below.
-d Delete an entry for the host called hostname. Alternatively, the
-d flag may be combined with the -a flag to delete all entries,
with hostname lookups automatically disabled. Only the superuser
may delete entries.
-F Force existing entries for the given host to be overwritten (only
relevant to the -f and -s options).
-f Process entries from filename to be set in the ARP tables. Any
entries in the file that already exist for a given host will not
be overwritten unless -F is given. Entries in the file should be
of the form:
hostname ether_addr [temp | permanent] [pub]
The entry will be static, i.e., will 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, responding to re-
quests for hostname even though the host address is not its own.
This behavior has traditionally been called proxy ARP.
-n Show network addresses as numbers (normally arp attempts to
display addresses symbolically).
-s hostname ether_addr [temp | permanent] [pub]
Create an ARP entry for the host called hostname with the Ether-
net address ether_addr. The Ethernet address is given as six hex-
adecimal bytes separated by colons. Lines beginning with '#' are
considered comments and are ignored.
The permanent, pub, or temp modifiers may be specified with mean-
ings as given above.
If the entry already exists for the given host, it will not be
replaced unless -F is given.
EXAMPLES
To view the current arp(4) 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:
# arp-s 204.1.2.3 00:90:27:bb:cc:dd pub
# arp-s 204.1.2.4 00:90:27:bb:cc:dd pub
(where 00:90:27:bb:cc:dd is the MAC address of fxp0)
SEE ALSOinet(3), arp(4), ifconfig(8)HISTORY
The arp command appeared in 4.3BSD.
MirOS BSD #10-current July 14, 1999 1
