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ICMP (Internet Control Message Protocol) in Computer Network

Computer Network | ICMP: In this tutorial, we will learn about the ICMP (internet control message protocol) in computer network. By IncludeHelp Last updated : June 11, 2023

Internet Control Message Protocol (ICMP) is a protocol used for communication between nodes on the Internet. It is an integral part of IP networking and is used to report errors, redirect data packets, and test network connections.

ICMP can also be used maliciously in DDoS attacks or as a means of data exfiltration. This tutorial will explore the features of ICMP, its applications, and how it is used both legitimately and maliciously.

It will also discuss the ping command which allows users to test network connections by sending out echo requests and receiving echo replies from remote systems.

What is Internet Control Message Protocol (ICMP)?

Internet Control Message Protocol (ICMP) is a network layer protocol used to control and manage queries, detect packet losses and delays, and facilitate error reporting and network diagnosis. ICMP packets are transmitted in datagrams that contain an IP header along with the ICMP data. The header includes the Type, Code, and Checksum fields.

Moreover, ICMP can be used to send messages regarding source quench, parameter problems, time exceeded, and destination unreachable; it also helps in redirecting data packets on alternate routes as well as supports IP for providing error control.

Furthermore, one can check whether a website is up and running or find out the IP address of any device using this protocol. Despite its usefulness though, ICMP can be blocked by firewalls making it vulnerable to DDoS attacks such as Ping of Death or Smurf attacks.

ICMP Header

The ICMP Header consists of a Type, Code, and Checksum field that facilitate the transmission of error control and management queries across the network.

  • The Type field denotes the type of message being sent, such as source quench, parameter problem, time exceeded or destination unreachable.
  • The Code field is used to differentiate among different types of messages to provide further detail about the issue at hand.
  • The Checksum field is used to verify data integrity on both ends by ensuring that no bits have been changed during transit. This ensures reliable communication between two devices over an unreliable connection.

ICMP is a crucial part of IP networks as it provides valuable information for troubleshooting issues and redirecting traffic onto alternate routes if one becomes unavailable.

It also serves as a powerful tool for system administrators who can use ICMP-based commands such as ping to detect packet loss or latency issues in order to ensure optimal performance of their networks.

Ultimately, ICMP enables successful communication between two devices separated by vast distances over the internet while providing mechanisms for error detection and correction along the way.

ICMP Attacks

Due to its connectionless nature, ICMP can be exploited for malicious purposes, such as launching various types of attacks. Amongst these are the Ping of Death, ICMP Flood, and Smurf attacks which use ICMP messages to overwhelm a targeted device or network.

  • The Ping of Death attack involves sending fragmented packets exceeding the maximum size allowed by IP (65,536 bytes) in an attempt to crash or freeze the target system.
  • An ICMP Flood is a denial-of-service attack that floods a target with ICMP echo requests (pings).
  • The Smurf attack works by sending a large number of ICMP echo request packets from spoofed source addresses, thus overwhelming the target with ping replies generated by other devices on the same network.

It is important to protect networks against these types of attacks as they can cause significant disruption and damage. Network administrators should be aware of common methods used in such attacks and take measures such as activating firewalls and monitoring traffic patterns to prevent them from occurring.

Securing devices with anti-virus software and applying patches on all systems regularly can also help reduce vulnerability to such threats.

Ping overview and its uses

Ping is an essential network utility that provides insights into the connection between devices on the internet. It is produced using Internet Control Message Protocol (ICMP) and used to check for a connection, detect packet loss and delays, and test the speed, latency, stability, quality, and throughput of a network connection. Ping can also be used by network administrators to troubleshoot problems with a network or website, find the IP address of a device, and assess whether a website is up and running.

Connection CheckUsed to determine if there's an active connection between two devices over the internet.
Packet Loss & Delays DetectionDetects packet loss and delays in transmission between two devices on the internet.
Speed TestingTests the speed, quality, latency, stability and throughput of a given network connection.
Troubleshooting Networks/WebsitesUsed by administrators to identify issues with networks or websites. Also helps with finding IP addresses of other devices connected to the same network.
Website Availability TestingCan be used to verify if a website is up or down at any given time.

By sending and receiving packets of information, the utility of Ping can be employed to assess various aspects of an existing network connection.

In addition, it can also be utilized to detect packet loss or delays that are inherent in certain networks. Network administrators use this tool to troubleshoot any issues with their systems as well as to determine whether websites are up and running. Furthermore, users may find out the IP address of a device by using this ping protocol. This is especially helpful if an IP address has recently changed on the system being pinged.

It should be noted that firewalls may block these messages which could prevent successful pings from taking place. Despite this limitation, Ping remains an important tool for assessing internet performance and diagnosing potential problems with connections across multiple devices.


The Internet Control Message Protocol is a powerful tool for network management and diagnosis. Its ability to detect errors, redirect data packets, and diagnose networks makes it an invaluable asset to network administrators. By understanding its features and capabilities, we can use ICMP more effectively to maintain efficient networks.

As with all power tools, the misuse of ICMP can be dangerous. Care must be taken to ensure that attacks are not mounted using this protocol as even the slightest misstep could have far-reaching consequences. Like an experienced craftsman who knows how to wield a hammer safely, one must possess the proper understanding of ICMP before attempting any activity related to it.


What is ICMP and how is it used in network communication?

ICMP is a network layer protocol used for error control and management, sending messages for source quench, parameter problem, time exceeded and destination unreachable. It supports IP and is used by routers to report errors and diagnose networks. Ping is an ICMP tool that can test speed, latency, stability and throughput of connections between devices on the internet.

What security measures can be taken to prevent ICMP attacks?

To prevent ICMP attack, it is important to have firewalls and other security measures in place. Firewalls can be used to block ICMP packets and thus protect the network from malicious activities. It is also important to regularly update network security software and monitor any unusual activity on the network.

How does ICMP interact with other protocols?

ICMP is a connectionless protocol that uses datagrams with IP headers and ICMP data to interact with other protocols. It supports IP, redirects data packets on alternative routes and sends messages for source quench, parameter problem, time exceeded, and destination unreachable. Humorously put - it helps keep the internet running smoothly!

What are the benefits of using ping for network diagnosis?

Ping is an effective network diagnostic tool, providing insight into the speed, quality, latency, stability and throughput of a connection. It can detect packet loss and delays as well as test if a website is up and running. Additionally, it helps to identify IP addresses of devices and allows for troubleshooting by network administrators. All of these benefits come with the use of Ping for network diagnosis.

What is the difference between ICMP and TCP/IP?

TCP/IP is a suite of protocols for communication between computers, while ICMP is a protocol used within the TCP/IP suite to send messages regarding network conditions. ICMP is used for error control and management queries, such as redirecting packets on alternate routes or reporting errors. Ping is produced using ICMP data packets to test connection speeds, latency and packet loss.

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