Dell Networking SONiC: Power Over Ethernet
Summary: This article explains about how to use Power over Ethernet (PoE) in Dell Networking SONiC Switches. This article uses a Dell SONiC Edge 4.1 PoE platform.
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Instructions
Prerequisites
We are using standard interface naming conventions to demonstrate the Concepts. See Dell article 202172 Dell Networking S-Series: Basic Interface Configuration - SONiC 4.0 for more information regarding interface naming
Index
Introduction
Power over Ethernet (PoE) technology allows IP telephones, wireless LAN access points, web cameras, and many other appliances to receive power and data over the existing LAN cabling without having to modify the existing Ethernet infrastructure.
PoE feature is supported in Dell Networking Edge Standard SONiC 4.0 and later versions.
NOTE: PoE features are supported on Dell N3248PXE-ON, E3248PXE-ON, and E3248P-ON switches in Dell SONiC 4.1.
Target use cases for PoE
With PoE, you can perform following actions:
- Provide power to requesting devices attached directly to the switch.
- Prevent some or all PoE ports from delivering power.
- Manage the amount of power that can be delivered on a PoE port.
- View the electrical measurements and power delivery status of the PoE ports.
- Restore PoE port to its normal state when it is in a fault state.
You can enable PoE only on copper ports. However, depending on the platform, all or some of the available copper ports can be eligible for PoE functionality.
Supported PoE specifications
802.3af and legacy support
The PoE enabled network switches intending to supply power (PSE) provide the PSE functionality as specified in the IEEE 802.3af specification. The devices drawing power (PD) implements the PD functionality of the IEEE 802.3af specification. The Enterprise SONiC PoE implementation conforms to the IEEE 802.3af PoE specification. In addition, legacy devices (non-IEEE 802.3af compliant) can also be powered up using the legacy detection feature.
802.3at - High-power applications
Enterprise SONiC PoE uses the PoE+ specification (IEEE 802.3AT), which allows power to be supplied to Class 4 PD devices that require power greater than 15.4 Watts and up to 30 Watts. PoE-enabled network switches and routers can be deployed with devices that require more power than the dot3af specification.
802.3bt and pre-802.3bt support
Pre-802.3bt enables 60 Watts of power-on devices which support this feature.
The 802.3bt specification introduces Type 3 and Type 4 devices allowing power levels up to 51 W for Type 3 PDs (60 W PSE) and up to 71.3 W (90 W PSE) for Type 4 PDs. Current is provided through all four twisted pairs in the network cable. The 802.3bt specification also introduces power classes 5-8.
Flexible power management
The SONiC PoE solution provides power management which supports power reservation, power prioritization, and power limiting. Administrators can assign a priority to each PoE port. When the PoE switch has less power available and more ports are required to supply power, higher priority ports receive power in preference to lower priority ports. Lower priority ports are forcibly stopped to supply power in order to provide power to higher priority ports. In the Dynamic Power Management feature, power is not reserved for a given port at any point of time. Class-based power management reserves a class-based amount of power for a PoE port. The power that is available with the PoE switch is calculated by subtracting the instantaneous power drawn by all the ports from the maximum available power. Thus more ports can deliver power simultaneously. This feature is useful to efficiently power on more devices when the available power with the PoE switch is limited.
Configure PoE.
Enable PoE.
By default, PoE is enabled on all ports. When enabled, PoE delivers power to an attached device. To disable PoE on a port or port range, enter the disable command. To reenable PoE, enter the command:
no poe disable
Configuration Syntax
admin@DELLSONiC:~$ sonic-cli DELLSONiC# configure DELLSONiC(config)# interface Eth slot/port[/subport] DELLSONiC(config-if-Eth)# no poe disable
Disable PoE in an interface.
admin@DELLSONiC:~$ sonic-cli DELLSONiC# configure DELLSONiC(config)# interface Eth slot/port[/subport] DELLSONiC(config-if-Eth)# poe disable
Sample Output
By default PoE is enabled on all ports. To disable PoE in port Eth 1/1, use the below command:
admin@DELLSONiC:~$ sonic-cli DELLSONiC# configure DELLSONiC(config)# interface Eth 1/1 DELLSONiC(config-if-Eth1/1)# poe disable
To enable PoE on port Eth 1/1, use command:
no poe disable
Set PoE detection mode
Use the detection mode to set the type of devices that PoE can detect and power on. By default, PoE powers up both IEEE standard devices and pre-IEEE legacy devices which were prestandard. If you restrict the PoE controller to detect only IEEE standard devices (poe detection dot3bt), you can return to the default detection setting by entering the command:
no poe detection
Configuration Syntax
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Eth slot/port[/subport]
DELLSONiC(config-if-Eth)# poe detection {Detection Mode}
Detection Mode
dot3bt Dot3bt detection dot3bt+legacy Dot3bt detection followed by Legacy detection
Sample configuration
By default the PoE detection mode is dot3bt+legacy. To use dot3bt in port Eth 1/1, use the below command:
admin@DELLSONiC:~$ sonic-cli DELLSONiC# configure DELLSONiC(config)# interface Eth 1/1 DELLSONiC(config-if-Eth1/1)# poe detection dot3bt
Configure PoE port priority.
Sometimes the switch may not be able to supply power to all connected devices. The port priority is used to determine which ports supply power if adequate power capacity is not available for all PoE-enabled ports. If ports are configured with the same priority level, a lower-numbered port has a higher priority.
When the switch is delivering peak power to some devices and you attach a new device to a high-priority port, power to a low-priority port is shut down, and the new device is powered up.
By default, a PoE-enabled port has low priority.
Configuration Syntax
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# interface Eth slot/port[/subport]
DELLSONiC(config-if-Eth)# poe priority {critical | high | low | medium}
Sample configuration
To set priority to high in port Eth 1/1, use the below command:
admin@DELLSONiC:~$ sonic-cli DELLSONiC# configure DELLSONiC(config)# interface Eth 1/1 DELLSONiC(config-if-Eth1/1)# poe priority high
Set power management
Use the power management command to set the algorithm used by the PoE port to deliver power to requested powered devices (PDs).
Configuration Syntax
admin@DELLSONiC:~$ sonic-cli
DELLSONiC# configure
DELLSONiC(config)# poe power management {power management options}
Power Management Options
Class Class based Power Management Dynamic Dynamic Power Management
Reset PoE port
Use the reset command to reset power-supply (PSE) operation on all PoE ports or on a specified PoE port. The port stops delivering power and performs the PoE detection and power delivery cycle again.
Configuration Syntax
DELLSONiC# poe reset Eth slot/port[/subport]
Sample configuration
To reset PoE in port Eth 1/1, use the below command:
DELLSONiC# poe reset Eth 1/1
Clear PoE counters
Use the clear counters command to clear PoE error counters on a specified port or on all ports.
Configuration Syntax
DELLSONiC# clear poe counters [Eth slot/port[/subport]
Sample configuration
To clear PoE port in port Eth 1/1, use the below command:
DELLSONiC# clear poe counters Eth 1/1
View PoE information
To display the current PoE configuration and the system-wide status information:
DELLSONiC# show poe Firmware Version : 3.52 Total Power Available : 2496 Watts Threshold Power : 2246.0 Watts Total Power Consumed : 1.0 Watts Usage Threshold : 90 % Power Management Mode : Dynamic
View the PoE port configuration.
DELLSONiC# show poe port info {all | interface slot/port}
DELLSONiC# show poe port info Eth 1/1 ------------------------------------------------------------------------------------------------------------- Class Class Output Output Output Fault Port Requested Assigned Power Current Voltage Temp Status Status (mW) (mA) (V) (C) ------------------------------------------------------------------------------------------------------------- Eth1/1 1 1 1900 34 56.4 N/A Delivering No Error Overload Counter : 0 Short Counter : 0 Power Denied Counter : 0 Absent Counter : 0 Invalid Signature Counter : 0
DELLSONiC# show poe port info all (Output trimmed for brevity) ------------------------------------------------------------------------------------------------------------- Class Class Output Output Output Fault Port Requested Assigned Power Current Voltage Temp Status Status (mW) (mA) (V) (C) ------------------------------------------------------------------------------------------------------------- Eth1/1 1 1 1900 34 56.3 N/A Delivering No Error Eth1/2 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/3 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/4 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/5 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/6 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/7 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/8 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/9 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/10 Unknown Unknown 0 0 0 N/A Searching No Error Eth1/11 Unknown Unknown 0 0 0 N/A Searching No Error
Affected Products
PowerSwitch E3200-ON Series, Dell EMC Networking N3200-ONArticle Properties
Article Number: 000218146
Article Type: How To
Last Modified: 20 ذو الحجة 1446
Version: 4
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