(ISC)2 Certified in Cybersecurity Practice Exam

Which protocol is standardized by the IETF to check the availability of a service or host?

1. Internet Message Protocol (IMP)

2. Internet Control Message Protocol (ICMP)

3. Integrated Control Management Protocol (ICMP)

4. Internet Service Control Protocol (ISCP)

The correct answer is: Internet Control Message Protocol (ICMP)

The Internet Control Message Protocol (ICMP) is standardized by the Internet Engineering Task Force (IETF) and is used primarily for network diagnostics and error reporting. One of its key functionalities is to provide a way for devices to send messages about the state of the network, including checking the availability of a service or host. This is commonly implemented through tools like ping, which utilizes ICMP echo request and echo reply messages to determine if a host is responsive and to measure the round-trip time for packets sent to that host. ICMP plays a critical role in maintaining the health and efficiency of IP networks by enabling devices to communicate information about network conditions. This protocol allows for the detection of issues such as unreachable hosts or network congestion, which are essential for troubleshooting and optimizing network performance. The other options do not represent standardized protocols recognized for checking service availability in the same context as ICMP. For example, the Internet Message Protocol is not relevant in this context, nor do Integrated Control Management Protocol or Internet Service Control Protocol have duties aligned with availability checks or addressing network status. Thus, ICMP is uniquely suited for the task described in the question.