ICMP and the Role of Ping and Traceroute
Understand the ICMP control protocol that sits beside IP, and how ping and traceroute use it to diagnose reachability and routing.
What Is ICMP?
The Internet Control Message Protocol (ICMP) carries control and error messages for the IP layer. It is not used to send application data; it reports problems like unreachable hosts and assists diagnostics.
ICMP Sits Beside IP
ICMP messages are wrapped in IP packets but ICMP is considered part of the network layer. Unlike TCP or UDP, it has no ports, only message types and codes.
All lessons in this course
- Understanding TCP/IP Model
- IP Addressing & Subnetting
- TCP and UDP Fundamentals
- ICMP and the Role of Ping and Traceroute