Wireshark, a network analysis tool formerly known as Ethereal, captures packets in real time and display them in human-readable format. Wireshark includes filters, color-coding and other features that let you dig deep into network traffic and inspect individual packets.
Wireshark is a powerful open source network analyser which can be used to sniff the data on a network, as an aide to troubleshooting network traffic analysis, but equally as an educational tool to help understand the principles of networks and communication protocols.
cyborg@cyborg:~$ sudo wireshark [sudo] password for cyborg:
This will Start Wireshark as root
Select an Interface Below Start Button And Then Click Start
Sniffer on your chosen interface has been started in our case (eth0) . After this we simply pinged from another system i.e 192.168.1.18