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parprouted(8) [debian man page]

PARPROUTED(8)						     Proxy ARP Bridging Daemon						     PARPROUTED(8)

NAME

       parprouted - Proxy ARP IP bridging daemon

SYNOPSIS

       parprouted [-d] [-p] interface [interface]

DESCRIPTION

       parprouted is a daemon for transparent IP (Layer 3) proxy ARP bridging.	Unlike standard bridging, proxy ARP bridging allows to bridge Eth-
       ernet networks behind wireless nodes. Normal L2 bridging does not work between wireless nodes because wireless does not know about MAC
       addresses used in the wired Ethernet networks. Also this daemon is useful for making transparent firewalls.

       The daemon listens for incoming ARP requests, and in case the location of the requested IP address is unknown, forwards them to other
       interfaces, as well as updates kernel ARP table with the received replies. When necessary, the daemon generates an ARP reply itself, which
       causes the stations to send traffic to the host daemon is running on. By automatically adding appropriate /32 routes to Linux kernel IP
       routing table for the hosts learned via ARP, daemon ensures that the Linux kernel will be able to route the packets to the destination host
       when it receives them without any need routing/subnetting manually.

       All routes entered by the daemon have a metric of 50.

       Unless you use -p switch, all entries in the ARP table will be refreshed (rechecked by sending ARP requests) every 50 seconds. This keeps
       them from being expired by kernel.

       Normally it takes about 60 ms for a bridge to update all its tables and start sending packets to the destination.

REQUIREMENTS

       This daemon can be used for unicast traffic only. I.e., DHCP is not supported.  Use software such as dhcrelay to "bridge" DHCP.

       You should have an IP address assigned on all of your interfaces that you do bridging on. There is no need for this address to be from the
       same networks as the bridged networks. Any dummy address will do.

       The system should have correct default route.

       parprouted requires "ip" program from iproute2 tools to be installed in /sbin. If it is installed in another location, please replace
       "/sbin/ip" occurances in the source with the correct path. As well you should have proc filesystem mounted in /proc because the daemon uses
       /proc/net/arp.

       parprouted is designed for and tested only with Linux 2.4.x kernels.

OPTIONS

       The list of interfaces to do bridging on should be given via the command line.

       The daemon accepts the following switches:

       -d, which stands for debugging. If you run it in debugging mode the daemon will not go to background and will print additional debugging
       information to stdout/stderr.

       -p, which makes all ARP entries to be permanent. This will also result in that ARP tables will not be refreshed by ARP pings.

EXAMPLE

       To bridge between wlan0 and eth0: parprouted eth0 wlan0

AUTHOR

	(C) 2004, Vladimir Ivaschenko <vi@maks.net>
	http://www.hazard.maks.net

parprouted							   January 2004 						     PARPROUTED(8)

Check Out this Related Man Page

ARPD(8) 						    BSD System Manager's Manual 						   ARPD(8)

NAME

     farpd -- ARP reply daemon

SYNOPSIS

     farpd [-d] [-i interface] [net ...]

DESCRIPTION

     farpd replies to any ARP request for an IP address matching the specified destination net with the hardware MAC address of the specified
     interface, but only after determining if another host already claims it.

     Any IP address claimed by farpd is eventually forgotten after a period of inactivity or after a hard timeout, and is relinquished if the real
     owner shows up.

     This enables a single host to claim all unassigned addresses on a LAN for network monitoring or simulation.

     farpd exits on an interrupt or termination signal.

     Note: The program name farpd has been changed in Debian GNU/Linux from the original name (arpd) to avoid name clash with other ARP daemons.

     The options are as follows:

     -d      Do not daemonize, and enable verbose debugging messages.

     -i interface
	     Listen on interface.  If unspecified, farpd searches the system interface list for the lowest numbered, configured ``up'' interface
	     (excluding loopback).

     net     The IP address or network (specified in CIDR notation) or IP address ranges to claim (e.g. ``10.0.0.3'', ``10.0.0.0/16'' or
	     ``10.0.0.5-10.0.0.15''). If unspecified, farpd will attempt to claim any IP address it sees an ARP request for.  Mutiple addresses
	     may be specified.

FILES

     /var/run/farpd.pid

SEE ALSO

     pcapd(8), synackd(8)

BUGS

     farpd will respond too slowly to ARP requests for some applications. In order to ensure that it does not claim existing IP addresses it will
     send two ARP request and wait for a reply. This slowness affects the nmap network scanning tool, and possibly others, which uses by default
     ARP when scanning local networks. The answers from farpd will come after the tool has timeout waiting for the ARP replies and, consequently,
     IP addresses claimed by farpd will not be discovered.

     Additionally, farpd sends the ARP replies to the broadcast address of the network and not to the host that send the ARP request. Some systems
     and applications (notably nmap) will not handled these requests and expect directed ARP replies (i.e. targeted specifically to the host that
     sent the request and not to the network)

AUTHORS

     Dug Song <dugsong@monkey.org>, Niels Provos <provos@citi.umich.edu>

								  August 4, 2001
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