16 Replies Latest reply on Nov 3, 2016 1:01 PM by doug_allen

    How to find out PoE output levels on a switch/port?

    doug_allen

      I have a slightly different kind of question for a change.  If you wanted to find out how much power is being supplied by PoE ports on a Cisco Catalyst switch, how would it be done?  I'd like to know the total amount that each switch is putting out and, if possible, how much each PoE port on the switch is putting out?  I know I can keep plugging devices in until it won't power any more, but I'd like some method that will allow for better planning and not leave me looking like a complete nut.  For the record, the switches are still running IOS 12 - with the exact version dependent upon the device, with one exception.  One of the switches is running 16.3.1, because it was brand new this summer.  Most of the switches are 2960's.

       

      If the method is dependent upon an IOS version, I'd still like to hear the method and know which version of IOS supports the parts that allow it to work correctly.  If the method requires custom pollers, I will have many more questions to ask and will not feel bad about looking somewhat dense, because I know others will learn from my questions and the answers to them.

       

      Thanks in advance and I will be asking Cisco much the same kind of questions.

        • Re: How to find out PoE output levels on a switch/port?
          ctlswadmin

          Doug,

           

          The best way to go about this might be custom pollers. Here's something quick I threw together to see if this is what you had in mind, I might be off on my approach here.

           

          Tested this on 11.5.3, should work on the .12 release.

           

          Select NodeName,SensorDisplayName,SensorValue,SensorUnit
          From APM_HardwareSensorAlertData
          Where  CategoryName LIKE '%power%'

           

           

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          • Re: How to find out PoE output levels on a switch/port?
            d09h

            Are you polling this MIB already (custom MIB polling)?

             

            CISCO-POWER-ETHERNET-EXT-MIB

             

            If nothing in that MIB reports the total power across all ports, perhaps a poller transform would be helpful (or SQL query to achieve the same result).

             

            This list looks promising:  ftp://ftp.cisco.com/pub/mibs/v2/CISCO-POWER-ETHERNET-EXT-MIB.my

             

            If you have any hunches from the above URL, you may be able to confirm with an SNMPwalk, or correlation of CLI output, or TAC case.

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            • Re: How to find out PoE output levels on a switch/port?
              John Handberg

              The built in EnergyWise reports may also have some of this information as long as you are collecting the data.

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                • Re: How to find out PoE output levels on a switch/port?
                  doug_allen

                  I don't believe we are currently collecting the EnergyWise information.  I don't remember seeing anything in the config about it anyway. I looked at several of the switches (via List Resources) and the EnergyWise box is not checked.

                   

                  A related question to the original one.  When I ssh'd into several of the switches and had it show the PoE information for the ports, it gave exact information on any Cisco device lugged into it (IP Phone, wireless AP), but on anything else, it was reporting it as 'Ieee PD' and having it as pulling full power (15.4 w).  Some of those devices (mostly IP video cameras) would've had little or no traffic in their field of view, they are tuned to go to lower fps and lower quality in that instance, but go back to full fps and quality if something enters it's field of view.  I would expect the cameras to pull less power when they are slowed down, but there is no signs of it from the switch inquiry.  Do I misunderstand something about the way the PoE works on the switch or is the switch unable to lower the power requirements because it is not a Cisco device and is listed as a generic IEEE af type device (what the Ieee PD indicates if I understood the IOS 12.2 documentation correctly)?

                    • Re: How to find out PoE output levels on a switch/port?
                      John Handberg

                      I think if it is reporting and IEEE level, they always get full power.  The connected device would have to be able to negotiate power levels for that to change.  Negotiations are usually on power up though.  This device may just "get" full 15.4W possible port output because it didn't ask for a different level.  We had that happen at my old job with security cameras attached.  They just didn't negotiate a level and got full power all the time.

                       

                      As for EnergyWise, I do recall enabling basic EnergyWise commands on all of my Cisco switches at the old job so they would report, and that may be why the reports worked for me.  I didn't do anything else special that would enable those if I recall correctly.

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                        • Re: How to find out PoE output levels on a switch/port?
                          doug_allen

                          Ok.  So it would appear that the switch is reporting as designed.  I guess I need to go through the systems doc on the cameras and see if they can communicate a need to adjust power level by talking to the switch.  I also get to go through the IOS doc to figure out what I need to enter into the config files to turn on EnergyWise on the switches (if anything).

                           

                          Now I'm wondering if I need to look at the pollers that Solarwinds is currently using to see the cameras.  They are registering as PoE and an IP device, but that is all.  We monitor connectivity through Solarwinds and use the vendor software for actually looking at video.  It may all be able to talk in a better manner than it is now (almost not at all).

                            • Re: How to find out PoE output levels on a switch/port?
                              John Handberg

                              Enabling EnergyWise at global switch level was one command.  I added a second to add keywords, bjuildings names in our case.  We never actually did schedules other than in the lab to experiment with.  We were mainly after the power consumption reports from the SolarWinds EnergyWise reports.

                               

                              It might not hurt to look at SolarWinds EnergyWise guide as well.  It talks about managing EnergyWise with NCM and NPM, but doesn't seem to talk about the reports.  I still think I needed to just enable it globally on the switches to get the reports working.  I did all the config commands manually in the lab initially, then pushed the commands out to production switches via NCM.

                              EnergyWise devices

                          • Re: How to find out PoE output levels on a switch/port?
                            doug_allen

                            I can report that of the two switches I have enabled EnergyWise upon, I am getting information from them to Solarwinds. I'm not getting all of the information that I would like to see, but I know must be there - since it is displayed if I "show power inline" while logged into the switches.  I haven't done any real tweaking of reports yet either, so I will see how that goes.  It may also be that the default pollers do not collect the information and they may need to be tweaked.

                        • Re: How to find out PoE output levels on a switch/port?
                          lynchnigel

                          Hi there

                           

                          hopefully this will help, quite an old thread though

                           

                          Cisco PoE Monitoring 

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