When i discuss about hacking tips and talk about getting network traffic of other host on your host many ,many people get confused. Believe me its very simple, suppose your host in the network in which victim host is present. You can pollute ARP cache of victim host to forward traffic designated for other host get forwarded to your host.
To understand the complete process, let us understand which happen when one host try to access other host in same network, when source host need mac address of destination host. ARP protocol come in place to get mac address of host by broadcasting IP address. I mean suppose host A(192.168.5.1) need to access host B(192.168.5.2), ARP on host A broadcast message ‘who has ip 192.168.5.2 tell me your mac‘ , in normal circumstances B will reply with its MAC address , but in case of ARP poising another attacker host suppose C , reply with its mac address pretending that ip belong to it. So the data that should go to B will go to C. And suppose ip forwarding is enabled on C , A will not notice any hacking but C is here Man in Middle.
I use arpspoof command to do this basic hacking
root# arpspoof -t 192.168.1.1 192.168.1.2
In above statement victim is 192.168.1.1(i example its host A), and 192.168.1.2 is what attacker pretend to be (In given example its host B) and this command will run on attacker machine(I given example host C)