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Mar 21 / Greg

Cisco RPS (Redundant Power Supply)

If you have Cisco switches you may have noticed that there is a little plate covering something on the back. This something would be the RPS port. Cisco has a few devices, RPS’, used to backup your standard power. If the power supply in your switch malfunctions, the RPS will kick in and provide power.

I’m going to talk about the RPS300 (PWR300-AC-RPS). This guy covers the majority of your older switch line:

  • Catalyst 2912 LRE XL
  • Catalyst 2924 LRE XL
  • Catalyst 2950-12
  • Catalyst 2950-24
  • Catalyst 2950C-24
  • Catalyst 2950G-12-EI
  • Catalyst 2950G-24-EI
  • Catalyst 2950G-24-EI-DC
  • Catalyst 2950G-48-EI
  • Catalyst 2950SX-24
  • Catalyst 2950T-24
  • Catalyst 2980G-A
  • Catalyst 3524-PWR XL
  • Catalyst 3550-12G
  • Catalyst 3550-12T
  • Catalyst 3550-24-FX
  • Catalyst 3550-24-SMI
  • Catalyst 3550-24-EMI
  • Catalyst 3550-48-SMI
  • Catalyst 3550-48-EMI
  • Catalyst 4224
  • There is very little functionality in these guys. There really is only a single button to put it into standby or active mode. If you want to plug or unplug an RPS cable to or from a switch, you have to put the RPS into standby mode. If you mash the button on the front the standby/active light will turn amber. You can then plug as much as you like. When you are done, hit the button again to go back to active mode. That’s pretty much it.

    The RPS will only power a single device at a time. It is really only there to cover you in the event of a power supply failure. Another note is that if you simply bump the plug and switch to RPS and are ready to return, the switch will reload when it switches back to main power.

    If you are dumping syslog messages from your switch, you can match and alert on the following messages:
    Internal PSU goes bad:

    PLATFORM_ENV-1-PWR: Faulty internal power supply detected

    RPS goes bad:

    PLATFORM_ENV-1-PWR: Faulty redundant power supply detected


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    1. Richard / May 16 2013

      I have a 3550 and am receiving the log message %PLATFORM_ENV-1-PWR: Faulty internal power supply detected. RPS is not setup. Since the switch is working, do you think this may be a bug or is the switch on the verge of failing? I have other switches at the site running the same IOS/hardware but they do not show this message. Thoughts?

    2. Richard / May 16 2013

      In addition, I cannot find any commands to run to check the specs on the power supply (output wattage, volts, etc). Is there a command I can run to compare this switch power supply to one that is not showing the error message?

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