ARP
Section: (8)
Updated: 09 Jan 1995
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NAME
arp - manipulate the system ARP cache
SYNOPSIS
arp [-v] [-t type] -a [hostname]
arp [-v] -d hostname ...
arp [-v] [-t type] -s hostname hw_addr [temp] [netmask aa.bb.cc.dd] [pub]
arp [-v] -f filename
DESCRIPTION
Arp
manipulates the kernel's ARP cache in various ways. The primary options
are clearing an address mapping entry and manually setting up one. For
debugging purposes, the
arp
program also allows a complete dump of the ARP cache.
OPTIONS
- -v
-
Tell the user what is going on by being verbose.
- -t type
-
When setting or reading the ARP cache, this optional parameter tells
arp
which class of entries it should check for. The default value of
this parameter is
ether
(i.e. hardware code
0x01
for
IEEE 802.3 10Mbps Ethernet
ARCnet (arcnet)
,
PROnet (pronet)
and
AX.25 (ax25)
- -a [hostname]
-
Shows the entries of the specified hosts. If the
hostname
parameter is not used,
all
entries will be displayed.
- -d hostname
-
Remove any entry for the specified host. This can be used if the
indicated host is brought down, for example.
- -s hostname hw_addr
-
Manually create an ARP address mapping entry for host
hostname
with hardware address set to
hw_addr
class, but for most classes one can assume that the usual presentation
can be used. For the Ethernet class, this is 6 bytes in hexadecimal,
separated by colons. When adding proxy arp entries (that is those with
the [pub]lish flag set a netmask may be specified to proxy arp for
entire subnets. Proxy arp for routing entire networks is not a good
protocol, but its sometimes useful so supported.
- -f filename
-
Similar to the
-s
option, only this time the address info is taken from file
filename
set up. The name of the data file is very often
/etc/ethers
, but this is not official.
The format of the file is simple; it
only contains ASCII text lines with a hostname, and a hardware
address separated by whitespace.
In all places where a
hostname
is expected, one can also enter an
IP address
in dotted-decimal notation.
FILES
/proc/net/arp,
/etc/ethers
AUTHOR
Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- FILES
-
- AUTHOR
-
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