|Manpage of ARP
ARP
Section: Linux Programmer's Manual (8)
Updated: 15 May 1996
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NAME
arp - manipulate the system ARP cache
SYNOPSIS
arp
[-vn]
[-H type]
[-i if]
-a
[hostname]
arp
[-v]
[-i if]
-d hostname
[pub]
arp
[-v]
[-H type]
[-i if]
-s hostname hw_addr
[temp]
arp
[-v]
[-H type]
[-i if]
-s hostname hw_addr
[netmask nm]
pub
arp
[-v]
[-H type]
[-i if]
-Ds hostname ifa
[netmask nm]
pub
arp
[-vnD]
[-H type]
[-i if]
-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, --verbose
-
Tell the user what is going on by being verbose.
- -n, --umeric
-
shows numerical addresses instead of trying to determine symbolic host, port
or user names.
- -H type, --hw-type 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).
Other values might include network technologies such as
ARCnet (arcnet)
,
PROnet (pronet)
,
AX.25 (ax25)
and
NET/ROM (netrom).
- -a [hostname], --display [hostname]
-
Shows the entries of the specified hosts. If the
hostname
parameter is not used,
all
entries will be displayed.
- -d hostname, --delete hostname
-
Remove any entry for the specified host. This can be used if the
indicated host is brought down, for example.
- -D, --use-device
-
Use the interface
ifa's
hardware address.
- -i If, --device If
-
Select an Interface. When dumping the ARP cache only entries matching the
Interface will be printed. Setting a permanent or temp ARP entry will be
used on the specified device. If no device is given, the kernels guess the
device from the routing table. For
pub
entries the specified interface is the interface on which ARP requests will
be answered.
NOTE:
This has to be different from the interface to witch the IP
Packages will be routed.
- -s hostname hw_addr, --set hostname
-
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
publish
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. If the
temp
flag is not supplied entries will be permanent stored into the ARP cache.
- -f filename, --file 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. Additionally the
pub, temp and netmask
flags can be used.
In all places where a
hostname
is expected, one can also enter an
IP address
in dotted-decimal notation.
Each complete entry in the ARP cache will be marked with the
C
flag. Permanent entries are marked with
M
and published entries have the
P
flag.
FILES
/proc/net/arp,
/etc/networks
/etc/hosts
/etc/ethers
SEE ALSO
rarp(8), route(8), ifconfig(8), netstat(8)
AUTHORS
Fred N. van Kempen, <[email protected]> with a lot of improvements
from net-tools Maintainer Bernd Eckenfels <[email protected]>.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- OPTIONS
-
- FILES
-
- SEE ALSO
-
- AUTHORS
-
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Time: 13:10:00 GMT, August 31, 1998