address resolution display and control
arp [ -n ] -a
arp [ -n ] -d hostname
arp [ -n ] -f filename
arp -i interface_name target_ipaddr
arp [ -n ] -s
[ temp] [ pub ]
The arp program displays and modifies the
IPv4-to-hardware address translation table, which is
normally maintained by the address resolution protocol (see
When hostname is the only argument, arp
displays the current ARP entry for
hostname. The host may be specified by name or by
number, using Internet dot notation (see
Options are interpreted as follows:
If the -n flag is specified, arp will not display
symbolic names, but instead will display
numeric Internet addresses.
Display all of the current ARP entries by reading the table
from the kernel.
Delete an entry for the host whose name is hostname.
(This can only be performed by root.)
Read the file filename and set multiple entries
in the ARP tables. Entries in the file should be
of the form
hostname hardware_addr [ temp ] [ pub ]
with argument meanings as
defined under the -s option.
-i interface_name target_ipaddr
Send an ARP request, avoiding the cache, on the specified interface
interface_name (for example, net0). In the broadcast
request, the sender's IP address is that of the interface,
the sender's hardware address (MAC address) is that of the interface,
and the target IP address is that specified by
On interfaces with aliased IP addresses (see
a separate ARP request is broadcast for each alias address
with the sender's IP address set to the alias address.
As generally used, the sender expects
the host with the target IP address to respond
with an ARP reply containing its hardware address.
If the sender and target IP addresses
are identical, a gratuitous ARP request is broadcast.
This allows other hosts on the network to update their cache entries
for the sender's IP address with the hardware address
contained in the request. No reply is expected.
If an interface has been configured with several alias IP addresses,
a separate gratuitous ARP request must be issued for each
IP address which needs to notify its corresponding
hardware address to the network.
-s hostname hardware_addr [ temp ] [ pub ]
Create an ARP entry for the host whose name is hostname
with the hardware address hardware_addr.
The hardware address is given as six colon-separated, two-digit
hexadecimal numbers. The entry will be permanent unless the argument
temp is specified on the command line.
If pub is specified, the entry will be ``published'':
that is, this system will act as an ARP server,
responding to requests for hostname
even though the host address is not an address of the local host.
Displays the ARP statistics that the kernel maintains;
these may be useful for debugging network problems.
for a list of messages that can come from the arp driver.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004