arpon(8)						      System Manager's Manual							  arpon(8)

NAME

       arpon - Arp handler inspectiON

SYNOPSIS

       arpon [ -npqfgiolcxsydevh ]

	     [ -n Nice value ] [ -p Pid file ]
	     [ -f Log file ]
	     [ -i Iface ]
	     [ -c Cache file ] [ -x Timeout ]
	     [ -y Timeout ]

DESCRIPTION

       ArpON (Arp handler inspectiON) is a portable handler daemon that make Arp secure in order to avoid Arp Spoofing/Poisoning & co.

       This  is  possible  using  two kinds of anti Arp Poisoning tecniques, the first is based on SARPI or "Static Arp Inspection", the second on
       DARPI or "Dynamic Arp Inspection" approach.

       SARPI and DARPI protect both bidirectional and distributed attacks. In "Bidirectional protection" is required that ArpON is  installed  and
       running	on  two nodes of the connection attached. In "Distributed protection" is required that ArpON is installed and running on all nodes
       of the connections attacked. All other nodes whitout ArpON will not be protected from attack.

       Keep in mind other common tools fighting ARP poisoning usually limit their activity only to point out the problem instead of  blocking  it,
       ArpON does it using SARPI and DARPI policies.  Finally you can use ArpON to pentest some switched/hubbed LAN with/without DHCP protocol, in
       fact you can disable the daemon in order to use the tools to poison the ARP Cache.

       Remember it doesn't affect the communication efficiency of the ARP protocol!

OPTIONS

       TASK MODE

       -n (--nice) <Nice Value>
	      Sets PID's CPU priority (Default: 0 nice).

       -p (--pid-file) <Pid file>
	      Sets the pid file (Default /var/run/arpon.pid).

       -q (--quiet)
	      Works in background task.

       LOG MODE

       -f (--log-file) <Log file>
	      Sets the log file (Default: /var/log/arpon.log).

       -g (--log)
	      Works in logging mode.

       DEVICE MANAGER

       ArpON is an ARP handler and it is able to handle network devices automatically (default) or manually, to print a list of up network  inter-
       faces of the system.

       It  identifies  the interface's datalink layer you are using but it supports only Ethernet/Wireless as datalink. It sets the netowrk inter-
       face and check running, online ready and it deletes the PROMISCUE flag. The online ready checks unplug (virtual and physical), boot, hiber-
       nation and suspension OS' features for Ethernet/Wireless card. It handles these features and reset the network interface automatically when
       it will ready.

       -i (--iface) <Iface>
	      Sets your Ethernet device manually.

       -o (--iface-auto)
	      Sets Ethernet device automatically.

       -l (--iface-list)
	      Prints all Ethernet devices.

       STATIC ARP INSPECTION

       When SARPI starts, it saves statically all the ARP entries it finds in the ARP cache in a static cache called SARPI Cache.  Note  that  you
       must  manage  the  ARP  through	the SARPI cache from file feature of ArpON.  After the startup, ArpON operations are split in two parallel
       tasks:

       - It automatically updates the ARP cache each time the timeout expires; timeout is simply the expire time of each entry in the  ARP  cache,
       defined according to the policy set in the running kernel.  Timeout is set by default to 10 minutes, but you can override this value.

       - It applies policies to the ARP cache, according to the following three schemes:

       1)  For	each received ARP reply, ArpON checks whether source addresses match an entry in the SARPI cache. In such case, the new entry will
       overwrite the old one, previously saved in the static cache.  Here, ArpON will defend and block ARP Poisoning/Spoofing attacks.

       2) For each received ARP request, ArpON checks wheter the source addresses match an entry in the SARPI cache. In such case, the	new  entry
       will overwrite the old one, previously saved in the static cache.  Here, ArpON will defend and block ARP Poisoning/Spoofing attacks.

       3) Every ARP request/reply whose source address doesn't match an entry in the SARPI cache are just ignored.

       Both  these  operations are a countermeasure against ARP Poisoning/Spoofing attacks, as SARPI detects and blocks them. SARPI doesn't affect
       the communication efficiency of the ARP protocol. SARPI just manages a list with static entries, making it an optimal choice in those  net-
       works without DHCP.

       Finally, it's possible to use SARPI as a daemon, using the "TASK MODE" and "LOG MODE" feature of ArpON.	It supports daemon exit by SIGINT,
       SIGTERM, SIGQUIT and daemon reboot by SIGHUP and SIGCONT POSIX signals.

       -c (--sarpi-cache) <Cache file>
	      Sets Arp Cache entries from file (Default: /etc/arpon.sarpi).

       -x (--sarpi-timeout) <Timeout>
	      Sets Arp Cache refresh timeout (Default: 10 minuts).

       -s (--sarpi)
	      Manages Arp Cache statically.

       DYNAMIC ARP INSPECTION

       DARPI startup phase consists in cleaning up the ARP cache, deleting all of its entries. This is due because ARP	cache  may  have  poisoned
       entries from the beginning.  DARPI handles the so called DARPI cache, applying different policies to different kinds of packets:

       - ARP request: It traces ARP requests and follows these rules if traffic is:

       1)  Outbound:  Packets  are  generated  by  us.	ArpON  let  them pass, adding an entry with the target to the DARPI cache (see ARP reply -
       Inbound).  On this DARPI cache entry, DARPI sets timeout because if this entry doesn't exist in network, DARPI must to delete it.

       2) Inbound: Packets come to us from the network. ArpON refuses the packet, deleting the entry of the source address  from  the  ARP  cache,
       because such packet may be poisoned. Afterwards, the kernel will send an ARP request to the source address, and it will be managed by ArpON
       through DARPI.  Here, ArpON will defend and block ARP Poisoning/Spoofing attacks through the ARP requests.

       - ARP reply: It traces the ARP replies, and follows these rules if traffic is:

       1) Outbound: Packets are generated by us. ArpON just lets them pass.

       2) Inbound: Packets come to us from the network. ArpON checks whether the source address matches an entry  in  the  DARPI  cache  (see  ARP
       request - Outbound), it lets the packet flow, adding an entry in the ARP cache. Otherwise, if the source address doesn't match any entry in
       the DARPI cache, ArpON refuses the packet, deleting the entry from the ARP cache.  Here ArpON defends  and  blocks  ARP	Poisoning/Spoofing
       attacks through the ARP replies.

       Both types of packets are used to perform ARP Poisoning/Spoofing attacks, as DARPI detects and blocks them. DARPI doesn't affect the commu-
       nication efficiency of the ARP protocol. DARPI manages uniquely a list with dynamic entries. Therefore it's an optimal solution in networks
       having DHCP.

       Finally, it's possible to use DARPI as a daemon, using the "TASK MODE" and "LOG MODE" feature of ArpON.	It supports daemon exit by SIGINT,
       SIGTERM, SIGQUIT and daemon reboot by SIGHUP and SIGCONT POSIX signals.

       -y (--darpi-timeout) <Timeout>
	      Sets DARPI Cache entry timeout (Default: 500 milliseconds).

       -d (--darpi)
	      Manages Arp Cache dynamically.

       MISC FEATURES

       Other.

       -e (--license)
	      Prints license page.

       -v (--version)
	      Prints version number.

       -h (--help)
	      Prints help summary page.

EXAMPLES

       - Static ARP Inspection:

	 Example of /etc/arpon.sarpi:

	   # Example of arpon.sarpi
	   #
	   192.168.1.1	   0:25:53:29:f6:69
	   172.16.159.1    0:50:56:c0:0:8
	   #

	 With 1 minut of timeout for arp cache refresh:

	   # root:ArpON-2.0 $ ./arpon -i en1 -x 1 -s

	     ArpON "Arp handler inspectiON" 2.0 (http://arpon.sourceforge.net)

	     12:55:03 - Wait link connection on en1...
	     12:55:12 - SARPI on dev(en1) inet(192.168.1.4) hw(0:23:6c:7f:28:e7)
	     12:55:12 - Arp Cache restore from /etc/arpon.sarpi...
	     12:55:12 - Protects these Arp Cache's entries:
	     12:55:12 - 1)     192.168.1.1 ->  0:25:53:29:f6:69
	     12:55:12 - 2)    172.16.159.1 ->	 0:50:56:c0:0:8
	     12:55:12 - Arp Cache refresh timeout: 1 minut.
	     12:55:12 - Realtime Protect actived!
	     12:55:22 - Request << Refresh entry 192.168.1.1 -> 0:25:53:29:f6:69
	     12:55:22 - Reply	>> Send to 192.168.1.1 -> 0:25:53:29:f6:69
	     12:55:39 - Request >> Send to 192.168.1.1 -> 0:0:0:0:0:0
	     12:55:39 - Reply	<< Refresh entry 192.168.1.1 -> 0:25:53:29:f6:69
	     12:56:03 - Request << Ignore entry 192.168.1.93 -> 0:23:6c:7f:28:e7
	     12:56:03 - Reply	>> Send to 192.168.1.93 -> 0:c:29:3:e5:98
	     12:56:12 - Refresh these Arp Cache entries:
	     12:56:12 - 1) 192.168.1.1 -> 0:25:53:29:f6:69
	     12:56:12 - 2) 172.16.159.1 -> 0:50:56:c0:0:8
	     ...

       - Dynamic ARP Inspection:

	   # root:ArpON-2.0 $ ./arpon -i en1 -d

	     ArpON "Arp handler inspectiON" 2.0 (http://arpon.sourceforge.net)

	     14:11:32 - Wait link connection on en1...
	     14:11:41 - DARPI on dev(en1) inet(192.168.1.4) hw(0:23:6c:7f:28:e7)
	     14:11:41 - Deletes these Arp Cache entries:
	     14:11:41 - 1)     192.168.1.1 ->  0:25:53:29:f6:69
	     14:11:41 - Cache entry timeout: 500 milliseconds.
	     14:11:41 - Realtime Protect actived!
	     14:11:41 - Request << Delete entry 192.168.1.1 -> 0:25:53:29:f6:69
	     14:11:41 - Reply	>> Send to 192.168.1.1 -> 0:25:53:29:f6:69
	     14:11:41 - Request >> Add entry 192.168.1.1
	     14:11:41 - Reply	<< Refresh entry 192.168.1.1 -> 0:25:53:29:f6:69
	     14:11:49 - Request >> Add entry 192.168.1.5
	     14:11:49 - Reply	<< Delete timeout entry 192.168.1.5
	     14:12:04 - Request >> Add entry 192.168.1.1
	     14:12:04 - Reply	<< Refresh entry 192.168.1.1 -> 0:25:53:29:f6:69
	     ...

AUTHOR

       ArpON was writen by:

		   Andrea Di Pasquale <spikey.it@gmail.com>

       The current version is available via http:

	    http://arpon.sourceforge.net

BUGS

       Please send problems, bugs, questions, desirable enhancements, patch, source code contributions, etc. to:

		   spikey.it@gmail.com

								   04 April 2010							  arpon(8)