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Average CPU ratio for Routers

I've always thought that a router's CPU shouldn't surpass 50% utilization in case debugs needed to be run. Is there any official word and/or doc from Cisco stating what the threshold should be? Thanks.


Re: Average CPU ratio for Routers

Yes, you can read instructions like

"Caution!! Because the debug apple eigrp-all command can generate many messages, use it only when the router's CPU utilization is less than 50 percent."


"Warning: Debugging should be carried out with extreme caution; otherwise, CPU utilization may increase considerably. Debugging should be turned on for not more than 5-10 seconds. Console logging, terminal logging, and logging to a syslog server should be disabled. Buffer logging should be enabled and logging buffer size increased. A good value for the size of logging buffer would be 128000 bytes."

on CCO.

But it always depends on particular debug command options and your router load.

The only general rule I know is: Be careful with debug.

A good trick (I don't remember where I read it but it works) is to issue "undebug all" first.

Then issue your "debug something" command and in the case your console is flooded with debug messages and router CPU is overloaded you just press upper arrow (or Ctrl-P) twice and enter and all debugs are stopped.



Re: Average CPU ratio for Routers

Another good advice is to use "logging buffered 100000" and "no logging console" before the debug commands, then issue what debug command you want and undebug all. After that you can review your debug output in the logg buffers with sho logging.

A similar method is to redirect the logging to a syslog server, "logging host ...", keeping the "no logging console" before issuing the debug commands.

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