Comparison and Analysis of ICMP protocol

ICMP is one of the basic network protocols. With the development of the network, the protocols are becoming more and more complex and constantly changing to adapt to the needs of the network. We will introduce it in detail below. Internet Control Message Protocol ICMP is used to report errors and control messages on behalf of IP addresses. IP addresses use the internet Group Management Protocol IGMP to tell routers that there are available hosts in a network guidance group.

ICMP protocol

ICMP Source suppression message: When the TCP/IP host sends data to another host, if the speed reaches the saturation of the router or link, the router sends an ICMP Source suppression message.

ICMP packet structure

Type: an 8-bit field indicating the ICMP data packet type.

Code: an 8-bit code field, indicating a function in the specified type. If there is only one function in a type, the code field is set to 0.

Check: A 16-bit check on the ICMP part of the data packet.

The additional data of the specified type changes with each ICMP type.

IGMP Protocol

IGMP information is sent to other routers so that each vro supporting multi-channel broadcasting can know which host group and which network.

IGMP protocol Package Structure

Version: IGMP version. The value is generally 0x1 h.

Type: IGMP message type. the 0x1 H type is a host Member request. It is used on a multicast router to specify that any member in a multi-level group polls a network. the 0x2 H type is called host Member report. It is used to publish members in a specified group on the host or to answer requests from host members of a vro.

Unused: unused domain names are set to zero by senders and ignored by recipients.

Verification: A 16-bit test of the IGMP header.

Group address: the host uses this group address to store IP multicast addresses in a host Member request. in host Member requests, the Group address is set to zero, and the hardware-level multi-channel broadcast address is used to mark the Host group.