Monitoring incoming PING Requests
Use the TCPDUMP command to monitor and report incoming PING requests to the screen. This is useful when debugging connectivity issues from a remote location.
tcpdump ip proto \\icmp
Internet Control Message Protocol (ICMP) is a protocol like TCP that is typically used for communication between network devices. A PING is an ICMP Echo Request with a corresponding Echo Reply, so filtering by the ICMP will show PING requests, along with any other ICMP traffic on the device.