PortPeeker is a freeware utility for capturing network traffic for TCP, UDP or ICMP protocols. With Port Peeker you can see what traffic is being sent to a given port, easily and quickly.
Once you have started PortPeeker you have to configure it as to what protocol and port (or just ICMP protocol as it doesn't use 'ports') to listen on. You can also configure PortPeeker as to what type of traffic events to record. For example if we want to listen for TCP port 80 traffic (http), we would configure PortPeeker to listen on TCP 80.