IGMP and ICMP

Theoretical technology: TCP/IP protocol family (4) ICMP and IGMP protocol!
I should first talk about the IP protocol. Later, considering the hierarchy, I should explain the support protocol in detail! Because IP is my favorite and also my pain! Haha!

I. ICMP protocol
Why use ICMP! What is the reason for using ICMP?
The IP address cannot be used! IP addresses cannot provide error control and auxiliary mechanisms (such as host management and query )!
For this reason, ICMP is very good at undertaking this task!
ICMP is an Internet Control Packet protocol, which provides the following functions: Error Reporting and query.
The ICMP packet sent by ICMP cannot be directly delivered to the next layer. It must be in the IP address header!
ICMP packets are classified into two types: 1 is the error report package and 2 is the query package.
The error report package can be divided into: 1) the end cannot reach 2) the source point is restrained 3) the timeout 4) Parameter Problem 5) change the route
The query package can be divided into: 1) Send back request and answer 2) timestamp 3) Address Mask 4) router inquiry and announcement
Emphasize 1: ICMP is an error reporting protocol and is not responsible for error correction!
This section describes several commands and troubleshooting tools in windows!
1. ping the command. I am not familiar with this! (For details, refer to the PING Attack Details !)
2. The tracert command may be generated by tracking the path from the source point to the end point of the package,
Open CMD and run tracert www.2cto.com to check the routers on your computer!
3. The command pathping is a combination of ping and tracert! Good stuff!
Ii. IGMP Protocol
Two terms:
1. Multicast: One Party sends messages to multiple parties for receiving! One-to-many data transmission is multicast!
2. multicast router: A Router capable of forwarding multicast packets!
To be honest, I learned a lot about IGMP! However, the role of IGMP is less important (but not adequate), but the IP address must have IGMP!
IGMP is not important but necessary! A little conflicted! Haha!
The IGMP protocol is also called the Internet group management protocol! Helps multicast routers create and update "Honest" Member tables related to each vro interface!
Concept: This is often the case in Network Communication: one-to-many multicast communication methods! On-demand video streaming! What kind of multicast is most commonly used in QQ? You can think of it! IGMP takes care of this! Then, the multicast router is designed to avoid broadcast communication, isolate broadcast domains, and save bandwidth costs. When multicast is used, multicast groups are stored in multicast routes in a table, IGMP helps to establish and maintain this table, and the so-called "Honest" members are stable in a group and receive and send data! People in our QQ group can either join or quit! No 1 will go in and 1 will come out!
There are three IGMP versions and three types of packages in version 2: 1) query 2) member report 3) Exit report
Queries are classified into general queries and special queries! A Multicast router can be a network device that supports the multicast protocol! All the switches of Cisco Systems, the quidway series switches of Huawei, and ZTE's products. If you need to implement the multicast function on the network, buy their stuff! Ask the guy who sells the device for details!
Run the netstat/nra multicast address command to find the multicast address supported by the device's interface. The range of the multicast address is 224.0.0.0-239.255.255.255! The division of IP addresses will be explained in detail later!
Note that IGMP only appears on the LAN! Its original package cannot pass through the router!