3com S7906E Instruccion De Instalación

 

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Configure a proper LSP retransmission interval to avoid unnecessary retransmissions. 

 

IS-IS messages cannot be fragmented at the IP layer because they are directly encapsulated in frames. 

Therefore, IS-IS routers in an area need to send LSPs smaller than the smallest interface MTU in this 

area.  

If the IS-IS routers have different interface MTUs, it is recommended to configure the maximum size of 

generated LSP packets to be smaller than the smallest interface MTU in this area. Otherwise, the 

routers have to dynamically adjust the LSP packet size to fit the smallest interface MTU, which takes 

time and affects other services. 

Follow these steps to specify LSP lengths: 

Enter system view 

–– 

Enter IS-IS view 

isis [ process-id ] [ vpn-instance 
vpn-instance-name ] 

–– 

Specify the maximum length of 
generated Level-1 LSPs or 
Level-2 LSPs 

lsp-length originate size [ level-1 | 
level-2 ] 

1497 bytes by default 

Specify the maximum length of 
received LSPs 

lsp-length receive size 

1497 bytes by default 

 

Since changed LSPs may trigger SPF recalculation, you can enable LSP flash flooding to advertise the 

changed LSPs before the router recalculates routes. Doing so can speed up network convergence. 

Follow these steps to enable LSP flash flooding: 

Enter system view 

–– 

Enter IS-IS view 

isis [ process-id ] [ vpn-instance 
vpn-instance-name ] 

–– 

Enable LSP flash 
flooding 

flash-flood [ flood-count flooding-count | 
max-timer-interval flooding-interval | [ level-1 | 
level-2 ] ] * 

Required  

Not enabled by 
default 

 

Follow these steps to enable LSP fragment extension: 

Enter system view 

––