How do I enable PoE on a Cisco switch?

Cisco switches are often designed to make life easy, but some of the options that come with them require configuration. If you don’t know how to manage the switch, you won’t be able to utilize everything it can do.

To that end, the instructions below are going to explain how to use PoE with a Cisco switch.

What Is PoE?

Before we get into PoE configuration, it might help to know a little more about PoE and how it works. It stands for “power over Ethernet,” and it’s a switch design that simplifies networking. With PoE, a switch can send power through the Ethernet cable, eliminating the need for direct power lines for endpoint devices.

Here’s an example. You can purchase a PoE wireless router. When you use the router, you can simply connect it to a PoE switch, and the router will not need an A/C adapter or plug to draw power. You only need the Ethernet cable. This means that you can plan your network without having to ensure that power outlets are near each endpoint device. It can save a lot of time and money.

Keep in mind that PoE comes in a few different forms. The standard depictions are PoE, PoE+, PoE++ (or UPoE), and High-Power PoE. The power output of each type of PoE ranges from 15.4W to 100W per port.

Of course, if you want to take advantage of PoE, you’ll need to know how to enable and configure PoE on your Cisco switch.

How Do I Enable It on a Cisco Switch?

Typically speaking, utilizing PoE ports on a Cisco switch is incredibly easy. The ports are enabled by default, and they are designed to act as plug-and-play ports. Here’s what happens when you plug a PoE device into an enabled PoE switch.

First, the switch will detect the PoE device. The device will try to draw power, and the switch will notice. When that happens, it will automatically adjust the flow of power according to the device’s needs. That allows the switch to use smart sensing to optimize power flow. This will prevent damage to devices that don’t need as much power, and it will prevent devices from consuming more power than is really necessary.

With all of that said, it is possible to disable PoE ports on Cisco switches. So, if you plug in a PoE device and automatic configuration does not make everything work easily, then you may need to manually change the PoE settings.

To do that, you will need to open up the terminal for your Cisco switch. You can find detailed instructions for that task here.

Once the terminal is open, you’re going to use the following commands to enable and even configure the PoE ports on your switch:

Enable the switch. To do that, type “switch> enable” in the terminal.
Next, you want to configure the switch. Type “switch# configure terminal” and press enter.
The switch is now ready to receive configuration instructions. The easiest option is to set the switch to auto configuration so that it will work as described above. To do that, type “switch(config-if)# power inline auto”. This will turn on auto configuration.
Lastly, you need to close out the commands by typing “switch(config-if)# end”. That completes the process.

You can choose other configuration options if you want to manually set power consumption limits or other settings. For a full list of options, you can follow this link.

How Do I Check My PoE Ports?

When troubleshooting or managing your network, you may want to check your PoE ports. You can ensure that they are enabled and see which settings are active on those ports. Doing that is pretty straightforward. You will once again want to open up the switch terminal so that you can type commands directly.

Once in the terminal, you can check ports by typing “switch# show power inline”. This will list PoE configuration settings for the ports, and you can ensure that everything is operating the way you prefer. If you want to change any settings, use the instructions in the previous section.

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