Cisco Systems WSC2960X48TDL manual Information about PoE, Power over Ethernet Ports

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Configuring PoE

Information about PoE

Information about PoE

Power over Ethernet Ports

A PoE-capable switch port automatically supplies power to one of these connected devices if the switch senses that there is no power on the circuit:

•a Cisco pre-standard powered device (such as a Cisco IP Phone or a Cisco Aironet Access Point)

•an IEEE 802.3af-compliant powered device

•an IEEE 802.3at-compliant powered device

A powered device can receive redundant power when it is connected to a PoE switch port and to an AC power source. The device does not receive redundant power when it is only connected to the PoE port.

After the switch detects a powered device, the switch determines the device power requirements and then grants or denies power to the device. The switch can also sense the real-time power consumption of the device by monitoring and policing the power usage.

Supported Protocols and Standards

The switch uses these protocols and standards to support PoE:

•CDP with power consumption—The powered device notifies the switch of the amount of power it is consuming. The switch does not reply to the power-consumption messages. The switch can only supply power to or remove power from the PoE port.

•Cisco intelligent power management—The powered device and the switch negotiate through power-negotiation CDP messages for an agreed-upon power-consumption level. The negotiation allows a high-power Cisco powered device, which consumes more than 7 W, to operate at its highest power mode. The powered device first boots up in low-power mode, consumes less than 7 W, and negotiates to obtain enough power to operate in high-power mode. The device changes to high-power mode only when it receives confirmation from the switch.

High-power devices can operate in low-power mode on switches that do not support power-negotiation CDP.

Cisco intelligent power management is backward-compatible with CDP with power consumption; the switch responds according to the CDP message that it receives. CDP is not supported on third-party powered devices; therefore, the switch uses the IEEE classification to determine the power usage of the device.

•IEEE 802.3af—The major features of this standard are powered-device discovery, power administration, disconnect detection, and optional powered-device power classification. For more information, see the standard.

•IEEE 802.3at—The PoE+ standard increases the maximum power that can be drawn by a powered device from 15.4 W per port to 30 W per port.

 

Catalyst 2960-X Switch Interface and Hardware Component Configuration Guide, Cisco IOS Release 15.0(2)EX

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Contents Americas Headquarters First Published July 10Page N T E N T S Contents Configuring Auto-MDIX41 Configuring System MTU Configuring EEE Viii Convention Description Document ConventionsBold font Element Vertical barsReader Alert Conventions Obtaining Documentation and Submitting a Service Request Related DocumentationXii Command Modes Information About Using the Command-Line InterfaceThis chapter contains the following topics Mode Access Method Prompt Exit Method About This Mode ConfigureQuit Ctrl-ZUsing the Help System Command or Action Purpose StepMode HelpNo and default Forms of Commands Understanding Abbreviated CommandsCLI Error Messages How to Use the CLI to Configure Features Configuration LoggingConfiguring the Command History Error Message MeaningRecalling Commands Changing the Command History Buffer SizeCommand or Action Enabling and Disabling Editing Features Disabling the Command History FeaturePrivileged Exec mode Terminal no historyEditing Commands through Keystrokes Editing Command Lines That Wrap Searching and Filtering Output of show and more Commands Access-listShow more command begin include exclude regular-expression Show more command begin include excludeCommand or Action Example OL-29034-01 Finding Feature Information Information About Configuring Interface CharacteristicsInterface Types This module contains the following topicsSwitch Ports Port-Based VLANsSwitch Virtual Interfaces Trunk PortsPower over Ethernet Ports EtherChannel Port GroupsUsing the Switch USB Ports USB Mini-Type B Console PortInterface Connections USB Type a PortsInterface Configuration Mode Connecting VLANs with the SwitchDefault Ethernet Interface Configuration FeatureDefault Setting Layer 2 or switching mode switchport command VLANs 1Interface Speed and Duplex Mode Speed and Duplex Configuration GuidelinesIeee 802.3x Flow Control How to Configure Interface Characteristics Configuring Interfaces ProcedureGigabit Ethernet port 1 on switch 1 is selected Either gigabitethernet 1/0/1Configure terminal Adding a Description for an InterfaceDescription string Show interfaces interface-id descriptionConfigure terminal Enters global configuration mode Configuring a Range of InterfacesInterface range port-rangemacro Verifies the configuration of the interfaces in the range Configuring and Using Interface Range MacrosDefine interface-range macroname Setting the Interface Speed and Duplex Parameters Configuring Ethernet InterfacesInterface range macro macroname Speed 10 100 1000 auto 10 NonegotiateConfiguring Ieee 802.3x Flow Control Command or Action PurposeEnd Returns to privileged Exec mode Configuring SVI Autostate ExcludeEnter interface configuration mode Switchport autostate exclude Shutting Down and Restarting the InterfaceAn SVI line state up or down Interface vlan vlan-id gigabitethernet interface-idConfiguring the Console Media Type This configuration applies to all switches in a stackConfigure terminal Line console Media-type rj45 End Shutdown Shuts down an interfaceConfiguring the USB Inactivity Timeout Configure terminal Enters the global configuration modeMonitoring Interface Characteristics Command PurposeShow interfaces interface-id status err-disabled Show interfaces interface-id switchportClearing and Resetting Interfaces and Counters Configuration Examples for Interface Characteristics Identifying Interfaces on a Stack-Capable Switch ExamplesConfiguring a Range of Interfaces Examples Adding a Description to an Interface ExampleSetting Interface Speed and Duplex Mode Example Configuring and Using Interface Range Macros ExamplesConfiguring the Console Media Type Example Configuring the USB Inactivity Timeout Example To disable the configuration, use these commandsStandards and RFCs Standard/RFC NoneTechnical Assistance Description Link Cisco IOS Release 15.02EX This feature was introducedRelease Modification OL-29034-01 Restrictions for Auto-MDIX Prerequisites for Auto-MDIXThis module contains the following sections Information about Configuring Auto-MDIX How to Configure Auto-MDIXConfiguring Auto-MDIX on an Interface Auto-MDIX on an InterfaceMonitoring Auto-MDIX Example for Configuring Auto-MDIX This example shows how to enable auto-MDIX on a portPrerequisites for Ethernet Management Ports Information about the Ethernet Management PortEthernet Management Port Direct Connection to a Switch Supported Features on the Ethernet Management PortHow to Configure the Ethernet Management Port Disabling and Enabling the Ethernet Management PortAdditional References What to Do NextBootloader commands Related TopicMIBs Document TitleOL-29034-01 Configuring LLDP, LLDP-MED, and Wired Location Service Lldp Supported TLVs Lldp and Cisco Switch StacksLldp and Cisco Medianet LLDP-MED Supported TLVs Wired Location Service Default Lldp Configuration Configuration GuidelinesConfigure terminal Lldp run Lldp run Enables Lldp globally on the switchLLDP, and enter interface configuration mode Enabling LldpConfiguring Lldp Characteristics Lldp transmit Enables the interface to send Lldp packetsLldp receive Enables the interface to receive Lldp packets Show lldp Verifies the configurationSwitchconfig# lldp holdtime Configuring LLDP-MED TLVs Command or Action Purpose StepLldp med-tlv-select End Copy running-config startup-config Lldp med-tlv-select Specifies the TLV to enableConfiguring Network-Policy TLV Configuration mode. The range is 1 toVoice voice-signalingvlan vlan-idcos Dscp dvalue none untaggedConfiguring Location TLV and Wired Location Service Show network-policy profile Verifies the configurationUse one of the following WayExit Returns to global configuration mode Information, and enter interface configuration modeUse one of the following Verifies the configuration Enters location information for an interfaceEnabling Wired Location Service on the Switch Command or Action Purpose ExampleNmsp enable Enables the Nmsp features on the switch Configuring Network-Policy TLV ExamplesNmsp notification interval attachment location Command Description Civic location OL-29034-01 Information about the MTU System MTU GuidelinesHow to Configure MTU Sizes Configuring the System MTUShow system mtu Verifies your settings Configuration Examples for System MTUReload Reloads the operating system Additional References for System MTU Configuring PoE Restrictions for PoEInformation about PoE Power over Ethernet PortsSupported Protocols and Standards Powered-Device Detection and Initial Power Allocation ClassPower Management Modes Power Monitoring and Power Policing Maximum Power Allocation Cutoff Power on a PoE Port How to Configure PoE Configuring a Power Management Mode on a PoE PortShow power inline Budgeting Power for Devices Connected to a PoE PortNever static max max-wattage Budgeting Power to All PoE ports No cdp run Optional Disables CDPBudgeting Power to a Specific PoE Port Configure terminal No cdp runSpecifies the physical port to be configured, and enter Configuring Power PolicingPower inline consumption wattage Power inline police actionlog errdisable Exit Show power inline police Show errdisable recoveryConfiguration mode Power inline police actionlog errdisableWhile still providing power to the port Power inline police action log-Generates a syslog messageDown the port and puts the port in the error-disabled state Configuration Examples for Configuring PoE Monitoring Power StatusBudgeting Power Example Information About EEE EEE OverviewHow to Configure EEE Default EEE ConfigurationEEE is disabled by default Restrictions for EEESpecifies the interface to be configured, and enter Power efficient-ethernet autoCommand Monitoring EEEThis example shows how to enable EEE for an interface Configuration Examples for Configuring EEEThis example shows how to disable EEE for an interface Feature History and Information for Configuring EEE OL-29034-01 D E PoE
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