🎁 New User? Get 20% off your first purchase with code NEWUSER20 · ⚡ Instant download · 🔒 Secure checkout Register Now →
Menu

Categories

Networking Intermediate

What is ICMP (Internet Control Message Protocol)?

A network protocol used for diagnostic and error reporting, including ping and traceroute functionality.

ICMP sends error messages and operational information between network devices. Ping uses ICMP Echo Request/Reply to test reachability and measure round-trip time. Traceroute uses ICMP Time Exceeded messages to discover the network path.

Common ICMP messages include Destination Unreachable, Time Exceeded, Redirect, and Source Quench. While essential for network diagnostics, ICMP is often restricted by firewalls to prevent information disclosure and DDoS amplification attacks.

Related Terms

BGP (Border Gateway Protocol)
The routing protocol that makes the internet work by exchanging routing information between autonomous systems.
HTTP/HTTPS
The protocol used for transferring web pages and data between browsers and servers, with HTTPS adding encryption.
Bandwidth
The maximum rate of data transfer across a network connection, measured in bits per second.
Traceroute
A network diagnostic tool that shows the path packets take from source to destination, listing each hop along the way.
IP Address
A unique numerical label assigned to each device on a computer network for identification and communication.
Network Monitoring
The practice of continuously observing network infrastructure to detect failures, performance degradation, and security threats.
 View All Networking Terms →