(ISC)2 Certified in Cybersecurity Practice Exam

What commonly used network protocol helps detect issues in network services?

1. Hypertext Transfer Protocol

2. File Transfer Protocol

3. Internet Control Message Protocol

4. Simple Network Management Protocol

The correct answer is: Internet Control Message Protocol

The Internet Control Message Protocol (ICMP) plays a vital role in network troubleshooting and management. It is primarily used to send error messages and operational information indicating success or failure when communicating with other IP addresses. For instance, when a host is unreachable or a time-out occurs, ICMP can relay these messages, allowing network administrators to identify issues in the routing or accessibility of network services. One of the most well-known utilities that utilize ICMP is the "ping" command, which tests the reachability of a host on a network and measures the round-trip time for messages sent to the destination. If the ping fails, it may indicate network issues, such as an offline device or improper routing. In contrast, the other protocols mentioned serve different primary purposes. Hypertext Transfer Protocol (HTTP) is used for transferring web pages, File Transfer Protocol (FTP) is dedicated to the transfer of files between systems, and Simple Network Management Protocol (SNMP) is primarily focused on network management and monitoring rather than troubleshooting. While SNMP does contribute to network health monitoring, it may not provide the specific error messages related to packet delivery issues that ICMP does. This distinction makes ICMP particularly effective for detecting issues in network services.