This article provides information on how to view the CPU utilization on J-series routers via CLI and SNMP.
Problem or Goal:
Juniper M and T-series routers utilize individual hardware components to cleanly separate operating system components, which include the routing-engine, forwarding-engine, and services-engine.
However, the J-series platform utilizes a single CPU to handle all three components in the system.
It also provides for clean separation of the three components. Each engine has its own protected processing and memory resources, so that processing conflicts are never an issue.
Due to this clean separation, beginning with Junos 8.0, some new commands and SNMP objects were included; specifically for the monitoring of CPU utilization on the J-series platforms.
For J-series, a single object or command that will show the total CPU usage for both the routing-engine and forwarding-engine combined, is not available. The two components have their own objects to monitor. For the routing-engine use the show chassis routing-engine command. This command is equivalent to the jnxOperatingCPU SNMP MIB object.
user@host> show chassis routing-engine Routing Engine status: Temperature 26 degrees C / 78 degrees F CPU temperature 51 degrees C / 123 degrees F DRAM 2048 MB Memory utilization 30 percent CPU utilization: User 0 percent Real-time threads 7 percent Kernel 4 percent Idle 89 percent Model RE-J6350-3400 Serial ID NM1742 Start time 2008-04-29 16:56:46 UTC Uptime 2 minutes, 20 seconds Load averages: 1 minute 5 minute 15 minute 0.08 0.07 0.03
user@host> show snmp mib walk jnxOperatingCPU jnxOperatingCPU.220.127.116.11 = 0 jnxOperatingCPU.18.104.22.168 = 0 jnxOperatingCPU.22.214.171.124 = 0 jnxOperatingCPU.126.96.36.199 = 0 jnxOperatingCPU.188.8.131.52 = 0 jnxOperatingCPU.184.108.40.206 = 0 jnxOperatingCPU.220.127.116.11 = 0 jnxOperatingCPU.18.104.22.168 = 4 < 22.214.171.124 represents the routing-engine if stand alone or node0 if in cluster mode jnxOperatingCPU.126.96.36.199 = 0 < 188.8.131.52 represents the routing-engine of node1, if in cluster mode
user@host> show snmp mib get .184.108.40.206.4.1.26220.127.116.11.18.104.22.168.0.0 jnxOperatingCPU.22.214.171.124 = 4
In addition to the routing-engine utilization, there is also the forwarding-engine utilization. This value is more important, in terms of actual traffic-affecting CPU utilization. For forwarding, use the show chassis forwarding command. This command is equivalent to the jnxFwddProcess SNMP MIB object. The most important of these within the jnxFwddProcess hierarchy are the real-time threads (OID .126.96.36.199.4.1.26188.8.131.52.2.0).
user@host> show chassis forwarding FWDD status: State Online Microkernel CPU utilization 0 percent Real-time threads CPU utilization 12 percent Heap utilization 23 percent Buffer utilization 5 percent Uptime: 3 minutes, 5 seconds