I'm a new junior Network Engineer at my company, and I've been going over the nexus switches we have installed. I had a couple questions about one command in particular, which is show environment <fex> temperature. Output seen below:
Dec 30, 2013 - The Show Environment command can be very helpful to alert you of potential. About your router's or switch's fan, power, and temperature. This can be shown by the 'show env all' IOS command. I suppose that you can pull these variables with SNMP on cat 3500 routers and switches. Everything else must be pulled with SNMP. Note that when you run that command on Cisco IOS it will more than likely just say temperature: OK.
SW1# sh environment fex 100 temperature
Temperature Fex 100:
-----------------------------------------------------------------
Module Sensor MajorThresh MinorThres CurTemp Status
(Celsius) (Celsius) (Celsius)
-----------------------------------------------------------------
1 Outlet-1 63 45 31 ok
1 Die-1 100 85 41 ok
Now I've seen several other posts regarding this command on other websites, and some also have Inlet-1 sensors. Is the reason I'm not seeing one here because of differing hardware versions? For example we have a 2248, and the other post I saw had a 2232.
Secondly, what is an acceptable temperature for the outlet and die sensors? I am assuming the die-1 sensor is the cpu itself, and the outlet is the hot aisle side of the switch. Any input is appreciated
How do you know if your remote router and switches are being cooled properly? Are the fans working? David Davis tells you how to see the environmental status of your Cisco routers and switches and how to be alerted when there is a hardware problem.
——————————————————————————————————————————————————-
What is the Show Environment command?
The Show Environment command can be very helpful to alert you of potential hardware issues. You will need to accesss this command in global Exec mode. Here are the options available for the Show Environment command:
As you can see, this command has a number of options. You can view the status of your router fans, power supply, system board temperature, and more. I should also point out that the options for this command vary based on the hardware that it is running on.
Have you ever entered a computer room and the temperature was so hot that it felt like an oven? Well, with one swift command you can display temperature and fan status and internal temperatures of your routers.
Let's look at three examples of the Show Environment command and how it displays information based on different routers and switches.
Display from a 3845 router:Display from a 2960 SwitchAlso, as you can see, the functionality of the Show Environment command varies from one hardware platform to another. For example, on the 3845 series, there are additional features, such as the multiple temperature sources and alert thresholds, that can be configured.
To read more about Show Environment, please see the Cisco IOS Show Environment Command Reference.
What can I do to be alerted if there is an environmental problem?
With SNMP in the Cisco IOS, you can be alerted to the environmental conditions that your router is able to monitor. By enabling SNMP on the router, it can send traps to an SNMP management station that alerts you when environmental thresholds are exceeded. To do this, use the envmon SNMP notification type, like this:
With this code, a trap would be sent to your SNMP management station for environmental alerts such as fan failure, temperature thresholds warnings, voltage notifications, or redundant power supply failures.
For additional information on Cisco IOS SNMP traps, please see the CiscoIOS SNMP Traps Supported and How to Configure Them documentation.ConclusionThe Show Environment command provides detailed information about your router's or switch's fan, power, and temperature. You can use SNMP in the Cisco IOS to send environmental traps to a network monitoring station. With proper monitoring, you can be sure to be alerted to any environmental issues affecting network equipment and prevent network outages before they occur.
David Davis has worked in the IT industry for 15+ years and holds several certifications, including CCIE, CCNA, CCNP, MCSE, CISSP, VCP. He has authored hundreds of articles and numerous IT training videos. Today, David is the Director of Infrastructure at Train Signal.com. Train Signal, Inc. is the global leader in video training for IT Professionals and end users.
Want to learn more about router and switch management? Automatically sign up for our free Cisco Routers and Switches newsletter, delivered each Friday!