High CPU behavior occurs when " show version detail " or “ show version detail |no-more ” is executed from the console, Telnet, or ssh.
show version detail
show version detail |no-more
This is specific to the following:
Running the "show version detail" or “show version detail | no-more” command generates high CPU usage. If executed with additional commands at the same time, the Routing Engine becomes overly busy and drops control of traffic packets such as OSPF, ISIS, etc.
In the example below, the output of the run show chassis routing-engine command reveals that available CPU was 96% before the command was executed, but was reduced to 5% after the command was executed.
run show chassis routing-engine
CPU Utilization BEFORE executing run support information command:
user@router> show chassis routing-engine Routing Engine status: Temperature 52 degrees C / 125 degrees F CPU temperature 65 degrees C / 149 degrees F DRAM 2048 MB (2048 MB installed) Memory utilization 37 percent 5 sec CPU utilization: User 1 percent Background 0 percent Kernel 3 percent Interrupt 0 percent Idle 96 percent 1 min CPU utilization: User 1 percent Background 0 percent Kernel 3 percent Interrupt 0 percent Idle 96 percent *****
CPU Utilization AFTER executing run support information command:
user@router> show chassis routing-engine Routing Engine status: Temperature 52 degrees C / 125 degrees F CPU temperature 65 degrees C / 149 degrees F DRAM 2048 MB (2048 MB installed) Memory utilization 37 percent 5 sec CPU utilization: User 35 percent Background 0 percent Kernel 60 percent Interrupt 1 percent Idle 5 percent 1 min CPU utilization: User 4 percent Background 0 percent Kernel 9 percent Interrupt 0 percent Idle 87 percent 5 min CPU utilization: User 1 percent Background 0 percent Kernel 4 percent Interrupt 0 percent *********
The " show version detail " command is known to increase the CPU while being run on these platforms. It is recommended to execute the "show version detail" command separate from an automation service that have additional operational commands. Instead, it is recommend to only use "show version".