Detailed introduction of OSPF header message

The experimental diagram is as follows 【 What is captured is R1 Of G0/0/0 Interface 】：

        

 

  The captured message is as follows ：

Src ： The original address 【 Indicate where the interface comes from 】,Dst： Purpose interface ip Address ,OSPF There are two reserved multicast addresses 224.0.0.5,224.0.0.6; among 224.0.0.5 finger ospf All routers and the message will be sent to all OSPF Router ;224.0.0.6 finger ospf All of the DR Router 【DR That is, specify the router , Follow up 】

ospf Head ：
version： Version number , The default is version 2; Of which version 2 Is for ipv4 To prepare the , And the version 3 Is for ipv6 To prepare the .

Message Type: There are message types 5 A type of ：Hello[Hello message ]（1）,DD[ Database description ] （2）,lSR[ Link status request ](3),LSU[ Link status update ]（4）,LSAck[ Link status confirmation ](5) -------[ I'll make a detailed introduction later ]

Packet Length: packet length , It refers to the whole OSPF message ; Contains only OSPF Head and Hello message 【 If the message is DD The message only contains OSPF Head and DD message 】.

Source OSPF Router : Router ID And the configured Router-ID【 Often used in practical work Loop 0 To configure the 】.

Area ID ：OSPF Area , Here it is represented as area 0; If area 1 Is represented as 0.0.0.1

Checksum : Check information , It is used by the peer router to check the integrity and legitimacy of the message .

Auth Type ： Authentication type 【Null： Indicates that there is no certification 】

Auth Data: Authentication information

Hello packet ：Hello message , I'll introduce it later .

Follow up articles will be updated within a week , Welcome to your attention . I will introduce in the most concise way IP knowledge

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