Provided by: arpon_3.0-ng+dfsg1-1_amd64 
NAME
ArpON - ARP handler inspection
IMPORTANT NOTICE
Since ArpON 3.0-ng (next generation), ArpON has been rewritten from scratch, therefore all
the old versions of ArpON (lower of 3.0-ng) are deprecated. Please upgrade all
installations of ArpON and read carefully the documentation specified below and this man
page of ArpON.
SYNOPSIS
arpon [OPTIONS] [SARPI ⎪ DARPI ⎪ HARPI]
DESCRIPTION
ArpON (ARP handler inspection) is a Host-based solution that make the ARP standardized
protocol secure in order to avoid the Man In The Middle (MITM) attack through the ARP
spoofing, ARP cache poisoning or ARP poison routing attack.
This is possible using three kinds of anti ARP spoofing techniques:
1) SARPI (Static ARP Inspection) for the statically configured networks without DHCP;
2) DARPI (Dynamic ARP Inspection) for the dynamically configured networks with DHCP;
3) HARPI (Hybrid ARP Inspection) for the statically and dynamically configured networks
with DHCP.
The goal of ArpON is therefore to provide a secure and efficient network daemon that
provides the SARPI, DARPI and HARPI anti ARP spoofing technique, thus making the ARP
standardized protocol secure from any foreign intrusion.
ArpON sets of policies in the ARP cache for all the static and or dynamic entries matching
the specified network interface (or that matching the several specified network interfaces
if run concurrently several daemons of ArpON for different network interfaces), through
the run of SARPI, DARPI or HARPI anti ARP spoofing technique.
ArpON have to be run with the root privileges. ArpON have to be configured using command-
line options and a configuration file. ArpON reloads the configuration of the specified
network interface and rereads its configuration file when it receives a hangup signal
(SIGHUP) by executing itself with the name and options it was started with. ArpON exits
correctly when it receives an interrupt signal (SIGINT) or a termination signal (SIGTERM).
IMPORTANT NOTE
The ArpON daemon sets two fundamental kernel network parameters via the sysctl interface
on the specified network interface:
1) The arp_ignore kernel parameter of the specified network interface is always set to 8
by ArpON. This is done to disable, in the specified network interface of the Operating
System, the sending of the ARP replies in response to received ARP requests for all local
addresses (the ARP replies on the specified network interface, will be sent by ArpON
instead of the Operating System).
2) The arp_accept kernel parameter of the specified network interface is always set to 0
by ArpON. This is done to disable, in the specified network interface of the Operating
System, the creating of the new IP entries in the ARP cache triggered by the unsolicited
and gratuitous ARP requests and replies (the IP entries in the ARP cache on the specified
network interface, will be created or updated by ArpON as static or dynamic IP entries
instead of the Operating System).
The ArpON daemon restores the previously values read from the arp_ignore and arp_accept
kernel parameters of the specified network interface when it receives an interrupt signal
(SIGINT) or a termination signal (SIGTERM). Remember to restore the values of the
arp_ignore and arp_accept kernel parameters of the specified network interface (the
default values are 0 for both), if you have terminated the ArpON daemon with other
signals, e.g. kill signal (SIGKILL).
OPTIONS SUMMARY
The available options are:
GENERAL OPTIONS
-d (--daemon)
Daemonize the ArpON.
-i (--interface) <interface>
Use the specified network interface.
SARPI 'STATIC ARP INSPECTION' OPTION
SARPI anti ARP spoofing technique manages and sets the policies in the ARP cache only for
all the static entries matching the specified network interface, in order to avoid the Man
In The Middle (MITM) attack through the ARP spoofing, ARP cache poisoning or ARP poison
routing. Therefore SARPI is an optimal choice in those statically configured networks
without DHCP. SARPI sets these policies:
1) CLEAN: SARPI cleans from the ARP cache only all the entries matching the specified
network interface, that are present or not present in the configuration file;
2) UPDATE: SARPI updates in the ARP cache only all the static entries matching the
specified network interface, that are present in the configuration file;
3) REFRESH: SARPI refreshes in the ARP cache only a static entry matching the specified
network interface, that is present in the configuration file;
4) ALLOW: SARPI sets up in the ARP cache only a dynamic entry matching the specified
network interface, that is not present in the configuration file.
Therefore SARPI requires a specified network interface and the specification in the
configuration file of the ARP cache only for all the static entries matching the specified
network interface.
-S (--sarpi)
Run SARPI anti ARP spoofing technique.
DARPI 'DYNAMIC ARP INSPECTION' OPTION
DARPI anti ARP spoofing technique manages and sets the policies in the ARP cache only for
all the dynamic entries matching the specified network interface, in order to avoid the
Man In The Middle (MITM) attack through the ARP spoofing, ARP cache poisoning or ARP
poison routing. Therefore DARPI is an optimal choice in those dynamically configured
networks with DHCP. DARPI sets these policies:
1) CLEAN: DARPI cleans from the ARP cache only all the entries matching the specified
network interface;
2) ALLOW: DARPI sets up in the ARP cache only a dynamic entry matching the specified
network interface;
3) DENY: DARPI cleans up from the ARP cache only a dynamic entry matching the specified
network interface.
Therefore DARPI requires a specified network interface and it doesn't requires any
specification in the configuration file of the ARP cache only for all the dynamic entries
matching the specified network interface.
-D (--darpi)
Run DARPI anti ARP spoofing technique.
HARPI 'HYBRID ARP INSPECTION' OPTION
HARPI anti ARP spoofing technique manages and sets the policies in the ARP cache for both
all the static and dynamic entries matching the specified network interface, in order to
avoid the Man In The Middle (MITM) attack through the ARP spoofing, ARP cache poisoning or
ARP poison routing. Therefore HARPI is an optimal choice in those statically and
dynamically configured networks with DHCP. HARPI sets and combines these policies of the
SARPI and DARPI:
1) CLEAN: HARPI cleans from the ARP cache only all the entries matching the specified
network interface, that are present or not present in the configuration file;
2) UPDATE: HARPI updates in the ARP cache only all the static entries matching the
specified network interface, that are present in the configuration file;
3) REFRESH: HARPI refreshes in the ARP cache only a static entry matching the specified
network interface, that is present in the configuration file;
4) ALLOW: HARPI sets up in the ARP cache only a dynamic entry matching the specified
network interface, that is not present in the configuration file;
5) DENY: HARPI cleans up from the ARP cache only a dynamic entry matching the specified
network interface, that is not present in the configuration file.
Therefore HARPI requires a specified network interface, the specification in the
configuration file of the ARP cache only for all the static entries matching the specified
network interface; instead it doesn't requires any specification in the configuration file
of the ARP cache only for all the dynamic entries matching the specified network
interface.
-H (--harpi)
Run HARPI anti ARP spoofing technique.
STANDARD OPTIONS
-v (--version)
Print the version and exit.
-h (--help)
Print the help screen and exit.
FILES
The available files are:
/etc/arpon.conf
The configuration file contains the configuration data of ArpON and it is used when
run the SARPI or HARPI anti ARP spoofing technique, for the specification in the
ARP cache only for all the static entries matching the specified network interface
(or that matching the several specified network interfaces if run concurrently
several daemons of ArpON for different network interfaces). This file should be
writable by root only but it is recommended (though not necessary) that it be
world-readable.
/var/log/arpon.log
The log file contains the log data of ArpON. If there are several daemons of ArpON
running concurrently for different network interfaces, this contains the log data
of all the daemons of ArpON. This file should be readable only by root, and need
not be readable by anyone else.
/var/run/arpon.pid
The pid file contains the process ID of ArpON. If there are several daemons of
ArpON running concurrently for different network interfaces, this contains the
process ID of the one started last. The content of this file is not sensitive; it
can be world-readable.
EXAMPLES
These examples shows how to use all three kinds of anti ARP spoofing techniques.
In the same host, we have three network interfaces with different subnet classes and we
would set the ARP cache for all the static and dynamic entries matching the eth0, wlan0
and eth1 network interfaces. This scenario requires the run concurrently of three daemons
of ArpON:
SARPI 'STATIC ARP INSPECTION' EXAMPLE
The eth0 network interface has the 192.168.1.2/24 IP address. We have only three static
entries of the ARP cache:
1) 192.168.1.1 at 58:ac:78:10:b9:77;
2) 192.168.1.3 at d4:be:d9:fe:8b:45;
3) 192.168.1.4 at 90:94:e4:bb:1c:10.
and we have no dynamic entries of the ARP cache. This is the ideal case where we have to
use the SARPI anti ARP spoofing technique, therefore specify in the configuration file of
the ARP cache only all the static entries matching the eth0 network interface:
$ sudo nano /etc/arpon.conf
Therefore:
#
# ArpON configuration file.
#
# See the arpon(8) man page for details.
#
#
# Static entries matching the eth0 network interface:
#
# First static entry:
192.168.1.1 58:ac:78:10:b9:77
# Second static entry:
192.168.1.3 d4:be:d9:fe:8b:45
# Third static entry:
192.168.1.4 90:94:e4:bb:1c:10
Daemonize the ArpON and run SARPI anti ARP spoofing technique on the eth0 network
interface:
$ sudo arpon -d -i eth0 -S
Read the log file:
$ sudo tail -f /var/log/arpon.log
Read the pid file:
$ cat /var/run/arpon.pid
DARPI 'DYNAMIC ARP INSPECTION' EXAMPLE
The wlan0 network interface has the 172.16.1.2/24 IP address. We have no static entries of
the ARP cache, and we have only dynamic entries of the ARP cache. This is the ideal case
where we have to use the DARPI anti ARP spoofing technique, therefore daemonize the ArpON
and run DARPI anti ARP spoofing technique on the wlan0 network interface:
$ sudo arpon -d -i wlan0 -D
Read the log file:
$ sudo tail -f /var/log/arpon.log
Read the pid file:
$ cat /var/run/arpon.pid
HARPI 'HYBRID ARP INSPECTION' EXAMPLE
The eth1 network interface has the 10.0.1.2/16 IP address. We have only two static entries
of the ARP cache:
1) 10.0.1.1 at 58:ac:78:88:1a:bb;
2) 10.0.10.1 at 90:94:e4:7e:f4:59.
and we have the rest of entries as dynamic entries of the ARP cache. This is the ideal
case where we have to use the HARPI anti ARP spoofing technique, therefore specify in the
configuration file of the ARP cache only all the static entries matching the eth1 network
interface:
$ sudo nano /etc/arpon.conf
Therefore:
#
# ArpON configuration file.
#
# See the arpon(8) man page for details.
#
#
# Static entries matching the eth0 network interface:
#
# First static entry:
192.168.1.1 58:ac:78:10:b9:77
# Second static entry:
192.168.1.3 d4:be:d9:fe:8b:45
# Third static entry:
192.168.1.4 90:94:e4:bb:1c:10
#
# Static entries matching the eth1 network interface:
#
# First static entry:
10.0.1.1 58:ac:78:88:1a:bb
# Second static entry:
10.0.10.1 90:94:e4:7e:f4:59
Daemonize the ArpON and run HARPI anti ARP spoofing technique on the eth1 network
interface:
$ sudo arpon -d -i eth1 -H
Read the log file:
$ sudo tail -f /var/log/arpon.log
Read the pid file:
$ cat /var/run/arpon.pid
DOCUMENTATION
Please see also the documentation file:
/usr/share/doc/arpon/index.html
It contains the retrieving tutorial; the building tutorial; the installation tutorial; the
user tutorial with many examples and scenarios; the development tutorial with the Activity
diagrams of the SARPI, DARPI and HARPI anti ARP spoofing technique and with modular source
code well commented; the bug report tutorial that takes you step-by-step through all of
the features of ArpON.
DEVELOPMENT AND BUGS
Please send questions, desirable enhancements, patch, source code contributions, problems,
bugs, etc... to author or via the Bug tracking system, as specified in the documentation
file specified above and in the official website:
http://arpon.sourceforge.net
AUTHOR
ArpON was written by Andrea Di Pasquale aka "spikey" <spikey.it@gmail.com>.
COPYRIGHT AND LICENSING
Copyright (C) 2008-2016 Andrea Di Pasquale <spikey.it@gmail.com>
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of
conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of
conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF MIND,
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
NOTES
The ArpON daemon is completely compatible with the ARP standardized protocol as described
in these official RFC documents:
1. RFC 826:
http://tools.ietf.org/html/rfc826
2. RFC 2131:
http://tools.ietf.org/html/rfc2131
3. RFC 3927:
http://tools.ietf.org/html/rfc3927
4. RFC 5227:
http://tools.ietf.org/html/rfc5227
The ArpON daemon sets the arp_ignore and the arp_accept fundamental kernel network
parameters via the sysctl interface as described in this official kernel document:
1. IP sysctl:
http://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt