Analysis of multicast knowledge in IGMP V2 package

MulticastTransmission: Implements point-to-point network connection between the sender and each receiver. If a sender transmits the same data to multiple recipients at the same time, only one copy of the same data packet is required. It improves data transmission efficiency. This reduces the possibility of network congestion.

IGMP V2 package: The following three types of packages are supported: query, report, and Leave. The purpose of adding a Leave package is to notify the router when the last member in the group leaves and quickly converge. in addition, the Query package can be divided into two types: A normal Query, which queries whether all groups have members (similar to V1); a special query, after receiving the Leave package, the query package sent by the router only queries the group;

Message Type (Type field) of IGMP V2 package)

1. query messages

Generral query

Group specific query

2. Version 1 member relationship report (v2 compatible with v1)

3. Version 2 member relationship report

4. Out-of-Group messages

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Maximum response time (10 seconds by default)

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Group address

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Host and group of IGMP V2 package

1. The host sends the member relationship report to 224.0.0.1.

2. All Hosts receive the report (the host sends a report every 10 seconds)

3. If the router receives the report, add the IGMP group ing table and forward traffic from the corresponding interface

4. the router sends a generral query every 60 seconds and sends it to all hosts to check whether there are any hosts in the group (ensure that at least one active host exists in the group)

5. When the host receives the generral query from the vro, it enables a random decline counter. When the counter is cleared, the host sends a membership report to respond to the generral query of the vro.

IGMP V2 package-out group

When the host wants to leave the multicast group, it will send a 4-type departure message (Address: 224.0.0.2) to the vro.

The vro sends a group specific message to check whether there are other hosts in the subnet that want to receive multicast group traffic.

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If the subnet does not have a dual-exit election query, the IP address with the highest interface will be elected

Another user who listens for the query (who does not respond in 120 seconds will think of himself as the queryer)

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IGMP timer for IGMP V2 package

1. query interval (queery interval 60 seconds by default)

 
 

  
  
R1 (config-if) # ip igmp query-interval? Modify
  
  
 
  
  
<1-65535>Query interval in seconds
 
 

2. query-timeout (the default value is 120 seconds)

 
 

  
  
R1(config-if)#ip igmp query-timeout ?  
  
  
 
  
  
<60-300> timeout value in seconds 
 
 

3. max response time (10 seconds by default)

 
 

  
  
R1(config-if)#ip igmp query-max-response-time ?  
  
  
 
  
  
<1-25> query response value in seconds 
 
 

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The content of the IGMP V2 package in the multicast knowledge is over. I hope you can understand it.

1. Horizontal split-by-the-command-by-product
2. Analysis of multicast knowledge-Layer 2 device forwarding Multicast
3. Instance resolution: the floating summary routing configuration of the VPN gateway.
4. Router POS access technology and Solutions
5. Configuration method of router log information record
6. For beginners, refer to the CISCO router tutorial.
7. Describes vro settings to ensure security