Скачать или смотреть CCNA CCNP Tutorial: What is ICMP. How Ping work | How Traceroute work

0:00 - Intro
This would be the introduction, likely covering the purpose and importance of understanding network protocols, with a specific focus on ICMP.

0:14 - What is ICMP
In this section, ICMP (Internet Control Message Protocol) would be explained. ICMP is a core part of the Internet Protocol (IP) suite used for sending error messages and operational information. It is crucial for diagnostics and network management. Examples of ICMP messages include "Destination Unreachable" or "Time Exceeded," which help diagnose network issues.

4:22 - ICMP Redirection
This section would dive into ICMP redirection, which occurs when a router informs a host that there is a better route to reach a destination. It's commonly seen in situations where a host is sending packets to the wrong router, and the network needs to redirect it to a more optimal route. It helps optimize network traffic and routing efficiency.

16:00 - How Ping Works
Here, you would learn about the ping utility, which uses ICMP Echo Request and Echo Reply messages to test the reachability of a host on an IP network. It is a tool for diagnosing network connectivity issues and measuring round-trip time. The section might cover the process of how a ping works, how the request is sent, and the reply received.

22:55 - How Traceroute Works
In this segment, Traceroute would be explained. Traceroute uses ICMP (or sometimes UDP) to track the path data takes from one machine to another. It works by sending a series of ICMP Echo Request packets with increasing TTL (Time-To-Live) values. Each router along the path returns an ICMP Time Exceeded message, and the final destination returns an ICMP Echo Reply. Traceroute provides information about each hop along the path and helps identify routing issues.

This outline covers some fundamental aspects of ICMP, focusing on its purpose, tools like ping and traceroute, and more advanced topics like ICMP redirection.