Example: Configuring PoE Interfaces with Different Priorities on an EX Series Switch

Requirements

This example uses the following software and hardware components:

• Junos OS Release 9.0 or later for EX Series switches
• One EX Series switch that supports PoE

Before you configure PoE, be sure you have:

• Performed the initial switch configuration. See Connecting and Configuring an EX Series Switch (CLI Procedure) or Connecting and Configuring an EX Series Switch (J-Web Procedure) for details.

Overview and Topology

The topology used in this example consists of a switch that has 24 ports. Eight of the ports support PoE (IEEE 802.3af), which means they provide both network connectivity and electric power for powered devices such as VoIP telephones, wireless access points, and IP security cameras that require 12.95 W or less. The remaining 16 ports provide only network connectivity. You use the standard ports to connect devices that have their own power sources, such as desktop and laptop computers, printers, and servers. Table 1 details the topology used in this configuration example.

Configuration

To configure PoE interfaces:

CLI Quick Configuration

By default, PoE interfaces are created for all PoE ports and PoE is enabled. The default priority for PoE interfaces is low.

To quickly set some interfaces to high priority and to include descriptions of the interfaces, copy the following commands and paste them into the switch terminal window:

Step-by-Step Procedure

1. Set the interfaces connected to high priority powered devices to high priority. Include the telemetries statement for the high priority interfaces, thus enabling the logging of power consumption on those interfaces:
   [edit poe]
user@switch# set interface ge-0/0/1 priority high telemetries
user@switch# set interface ge-0/0/2 priority high telemetries
user@switch# set interface ge-0/0/3 priority high telemetries
user@switch# set interface ge-0/0/4 priority high telemetries

2. Provide descriptions for the PoE interfaces:
   [edit interfaces]
user@switch# set ge-0/0/0 description "wireless access point"
user@switch# set ge-0/0/1 description "security camera front door"
user@switch# set ge-0/0/2 description "security camera back door"
user@switch# set ge-0/0/3 description "emergency phone"
user@switch# set ge-0/0/4 description "Executive Office VoIP phone"
user@switch# set ge-0/0/5 description "staff VoIP phone"
user@switch# set ge-0/0/6 description "staff VoIP phone"
user@switch# set ge-0/0/7 description "staff VoIP phone"
3. Connect the wireless access point to interface ge-0/0/0. This interface uses the default PoE settings.
4. Connect the two security cameras to interfaces ge-0/0/1 and ge-0/0/2. These interfaces are set to high priority with telemetries enabled.
5. Connect the emergency VoIP phone to interface ge-0/0/3. This interface is set to high priority with telemetries enabled.
6. Connect the Executive Office VoIP phone to interface ge-0/0/4. This interface is set to high priority with telemetries enabled.
7. Connect the staff VoIP phones to ge-0/0/5, ge-0/0/6, and ge-0/0/7. These interfaces use the default PoE settings.

Results

Check the results of the configuration:

[edit]
user@switch# show
interfaces {
    ge-0/0/0 {
        description "wireless access point";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/1 {
        description "security camera front door";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/2 {
        description "security camera back door";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/3 {
        description "emergency phone";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/4 {
        description "Executive Office VoIP phone";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/5 {
        description "staff VoIP phone";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/6 {
        description "staff VoIP phone";
        unit 0 {
            family ethernet-switching;
        }
    }
    ge-0/0/7 {
        description "staff VoIP phone";
        unit 0 {
            family ethernet-switching;
        }
    }
}
poe {
    interface all;
    interface ge-0/0/1 {
        priority high;
        telemetries;
    }
    interface ge-0/0/2 {
        priority high;
        telemetries;
    }
    interface ge-0/0/3 {
        priority high;
        telemetries;
    }
    interface ge-0/0/4 {
        priority high;
        telemetries;
    }
}

Verification

To verify that PoE interfaces have been created and are operational, perform the following tasks:

• Verifying That the PoE Interfaces Have Been Created with the Correct Priorities

Verifying That the PoE Interfaces Have Been Created with the Correct Priorities

Purpose

Verify that the PoE interfaces on the switch are now set to the correct priority settings.

Action

List all the PoE interfaces configured on the switch:

Interface Admin        Oper        Max       Priority Power             Class
          status       status      power              consumption
 ge-0/0/0 Enabled      ON          15.4W     Low      7.9W                0
 ge-0/0/1 Enabled      ON          15.4W     High     4.8W                0
 ge-0/0/2 Enabled      ON          15.4W     High     4.8W                0
 ge-0/0/3 Enabled      ON          15.4W     High     3.3W                2
 ge-0/0/4 Enabled      ON          15.4W     High     4.7W                2
 ge-0/0/5 Enabled      ON          15.4W     Low      3.2W                2
 ge-0/0/6 Enabled      ON          15.4W     Low      3.3W                2
 ge-0/0/7 Enabled      ON          15.4W     Low      3.3W                2

Meaning

The show poe interface command lists PoE interfaces configured on the switch, with their status, priority, power consumption, and class. This output shows that eight PoE interfaces are enabled. Interfaces ge-0/0/1 through ge-0/0/4 are configured as priority high. The remaining PoE interfaces are configured with the default priority value of low.