RID-- The router ID

Meet the conditions ：1. The whole network is unique 2. use the same pattern

Access method ：1. Manual configuration 2. Automatic generation Select one of the interfaces IP Address as RID( There are multiple loopback interfaces , Select the maximum value as RID. There is no loopback interface , Take the largest value of physical interface IP Address as RID)

OSPF Data packets

1.hello package ： Periodic Keep alive Discover building neighborhoods

hello Time ---10s or 30s( Depending on the type of network )

Deadtime---4 Times hello Time

2. DBD package ： Database description message , Link state database LSDB, Link status notification LSA

3.LSR package ： Link status request message

4.LSU package ： Link state update message , Really carry LSA Packets of information

5.LSAck package ： Link status acknowledgement message

OSPF There is 30min A periodic update

OSPF State machine

 TWO-WAY--- Mark the establishment of neighbor relationship

Condition matching process ： The match is successful , Go to the next stage . otherwise , Stay in the neighborhood , Use only hello Bao Huo Bao .

  Primary storage relation election ： Compare RID size , Give priority to the next stage ;( Implicit confirmation )

FULL state ---- Sign adjacency relationship establishment

OSPF Working process of

  Structural mutation ：

1. Add a new network segment ： Trigger update

2. Disconnect a network segment ： Trigger update

3. Unable to communicate ： here we are Deadtime

OSPF The basic configuration of