Solved: Problem is - SSH process consumes lot of cpu utilization

durgeshk · ‎06-02-2009

Hello, I am very fed up of when SSH process of switches in a LAN consumes a lot of processor utilization. Please suggest me to get rid of this problem.

Joseph W. Doherty · ‎06-03-2009

Glen makes an excellant point.

For a L2 switch, there's often not much for the processor to do since normal frame switching likey is done with ASICs.

For a L3 switch, the processor often has more "control plane" functions to contend with that can need processor resources. Something like SSH could compete for processor cycles, but even then, a good task scheduler should keep SSH process consumption being adverse to more critical functions.

If your issue is some thing like NMS is flagging high switch CPU when SSH is used, you might try adjust its thresholds. Otherwise, if you really consider this an issue, as James suggests, don't use SSH.

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pompeychimes · ‎06-02-2009

Stop using SSH.

glen.grant · ‎06-03-2009

Its not hurting anything and will only be elevated while you are SSH'd into the box . Unless the processor is already buried from some other process then its not hurting anything. Most traffic is switched in hardware these days and never even hits the cpu so its not affecting traffic flow to any big degree. It's going to elevate it a little because it has to highly encrypt all the commands you send to it using SSH .

Joseph W. Doherty · ‎06-03-2009

Glen makes an excellant point.

For a L2 switch, there's often not much for the processor to do since normal frame switching likey is done with ASICs.

For a L3 switch, the processor often has more "control plane" functions to contend with that can need processor resources. Something like SSH could compete for processor cycles, but even then, a good task scheduler should keep SSH process consumption being adverse to more critical functions.

If your issue is some thing like NMS is flagging high switch CPU when SSH is used, you might try adjust its thresholds. Otherwise, if you really consider this an issue, as James suggests, don't use SSH.

bretjaquish · ‎06-03-2009

What modulus size did you choose for your SSH keys? You could try decreasing down to no lower than 1024.

durgeshk · ‎06-07-2009

Hi,

Thanks for your reply, I always use 1024 should I need to decrease it.