tcpdump is the most powerful and widely used command-line packet sniffer (packet analyzer) tool available on Linux.
In the terminal application of the computer you want to monitor:
sudo tcpdump -i ethX icmp and icmp[icmptype]=icmp-echo
Options:
-n avoid a (potentially slow) reverse DNS query
−i interface
icmp[icmptype]=icmp-echo To print all ICMP packets that are echo requests/replies
It will start listening on ethX and wait for incoming packets.
Example: I have 2 PCs, Win7 with IP 192.168.0.8 and Ubuntu with IP 192.168.0.57. It will monitor incoming packets:
On Win7:
ping 192.168.0.57
On Ubuntu:
tcpdump -i eth0 icmp and icmp[icmptype]=icmp-echo -n
Reference: nixCraft[1]