arp - address resolution display and control
arp [-n] hostname
arp [-n] -a
arp -d hostname
arp -d -a
arp -s hostname ether_addr [temp | permanent] [pub]
arp -f filename
The arp program displays and modifies the Internet-to-Ethernet address
translation tables used by the address resolution protocol
With no flags, the program displays the current ARP entry
The host may be specified by name or by number, using Internet dot notation.
-a Display all of the current ARP entries. See also
the -d option
-d Delete an entry for the host called hostname. Alternatively, the
-d flag may be combined with the -a flag to delete
with hostname lookups automatically disabled. Only
may delete entries.
Process entries from filename to be set in the ARP
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,
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
i.e., this system will act as an ARP server, responding to requests
for hostname even though the host address is
not its own.
This behavior has traditionally been called proxy
-n Show network addresses as numbers (normally arp attempts to display
-s hostname ether_addr
Create an ARP entry for the host called hostname
with the Ethernet
address ether_addr. The Ethernet address is
given as six
hexadecimal bytes separated by colons.
The permanent, pub, or temp modifiers may be specified with meanings
as given above.
To view the current arp(4) table:
$ arp -a
To create a permanent entry (one that cannot be overwritten
by other network
# arp -s 10.0.0.2 00:90:27:bb:cc:dd permanent
To create proxy ARP entries on an interface, fxp0, for the
126.96.36.199 and 188.8.131.52:
# arp -s 184.108.40.206 00:90:27:bb:cc:dd pub
# arp -s 220.127.116.11 00:90:27:bb:cc:dd pub
(where 00:90:27:bb:cc:dd is the MAC address of fxp0)
inet(3), arp(4), ifconfig(8)
The arp command appeared in 4.3BSD.
OpenBSD 3.6 July 14, 1999
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