(ISC)2 Certified in Cybersecurity Practice Exam

What is it known when a ping request is successfully received?

1. ICMP Echo Reply

2. ICMP Echo Response

3. ICMP Echo Request

4. ICMP Echo Init

The correct answer is: ICMP Echo Reply

When a ping request is successfully received, it is referred to as an ICMP Echo Reply. The Internet Control Message Protocol (ICMP), which operates at the network layer, is used to send messages between devices about the status of the network. In the context of the ping command, a "ping" essentially sends an ICMP Echo Request to a specific destination. When that destination receives the request, it responds with an ICMP Echo Reply, indicating to the sender that the request has successfully arrived. This process confirms network connectivity between the sender and the destination. The term "ICMP Echo Reply" specifically denotes the response generated by the device receiving the ping, reaffirming that it is operational and reachable. The other terms do not accurately describe the response received when a ping is successful. For instance, "ICMP Echo Response" is a less commonly used term, while "ICMP Echo Request" refers to the original message sent, and "ICMP Echo Init" is not a recognized term within the context of ICMP communications. Thus, understanding the terminology associated with ICMP helps clarify network status and troubleshooting processes.