Junos OS

Hello Experts

What are flow and task CPU in JUNOS?

How I can troubleshoot the flow and task CPU in JUNOS?

Hello ,

The Junos software basically divides the system intyo control plane and dataplane , where control plane handles the process running in the device (Routing Engine ) and the Dataplane which deels with packet forwarding  ( forwarding plane )  .

They have 2 diff CPUs  :

> show chassis routing-engine  --> gives you the Control Plane CPU

> show security monitoring   --> gives you the dataplane CPU

Hello Sam

Thanks. To check which process is taking high control plane CPU we use show system process and using kill -9 <process id> we can kill the process that is taking high cpu cyles or process is stuck.

How we can do that for forwarding engine? Means which flow is taking high cpu cylce and how to kill that?

Hello ,

In Dataplane high CPU cases , we do not have any process to kill . This issue is mainly due to high traffic rate or an interface is hitting more amount of traffic that it can handle.  Or it can be due to IDP or Screen processing .  So Dataplane CPu is pritty straight forward .

Try checking these and also try disablig IDP and Screen .

Thanks. There is any shell command for forwarding eninge checking? I used show chassis forwarding command to check the CPU for forwarding engine. 

Hello ,

You can run :

 # show xlr cpu

this should be run in VTY on SPC card .