ICMP (Internet Control Message Protocol) is used in network devices, like routers, to send error
messages and operational information indicating success or failure when communicating with
another IP address.
An ICMP type 8 packet specifically is an "Echo Request." It is used primarily by the ping command to
test the connectivity between two nodes.
When a device sends an ICMP Echo Request, it expects to receive an ICMP Echo Reply (type 0) from
the target node. This mechanism helps in diagnosing the state and reachability of a network on the
Internet or within a private network.
Reference
RFC 792 Internet Control Message Protocol: https://tools.ietf.org/html/rfc792
Internet Assigned Numbers Authority (IANA) ICMP Parameters:
