The following restrictions apply to perpetual PoE:

• If the new Cisco IOS software image requires an M3 or power-sourcing equipment (PSE) upgrade during a system reload, the software image performs an upgrade, resulting in M3 or PSE resets, and the perpetual PoE ports lose power.

• If a power supply is removed during a system reload resulting in insufficient power, either the line card shuts down, or PoE load shedding occurs to compensate for the power loss. Perpetual PoE-configured ports might also lose power.

• If a powered device is removed and inserted back during a chassis reload, the powered device will not receive power till the software image boots up.

• Perpetual PoE is supported only on Cisco Catalyst 9400 Series Supervisor 2 Module (C9400X-SUP-2) and Cisco Catalyst 9400 Series Supervisor 2XL Module (C9400X-SUP-2XL).

This example shows how you can configure perpetual PoE on a switch:

Device> enable
Device# configure terminal
Device(config)# interface gigabitethernet2/0/1 
Device(config-if)# power inline port perpetual-poe-ha
Device(config-if)# end

The following sample output of the show power inline interface-id detail command displays perpetual PoE status:

Device# show power inline TenGigabitEthernet7/0/27 detail

Interface: TenGigabitEthernet7/0/27
Inline Power Mode: auto
Operational status (Alt-A,B): on
Device Detected: yes
Device Type: Ieee PD
Connection Check: SP
IEEE Class (Alt-A,B): 3
Physical Assigned Class (Alt-A,B): 3
Discovery mechanism used/configured: Ieee and Cisco
Police: off
 
Power Allocated
 Admin Value: 90.0
Power drawn from the source: 15.4
Power available to the device: 15.4
Allocated Power (Alt-A,B): 15.4
 Actual consumption
Measured at the port(watts) (Alt-A,B): 14.7
Maximum Power drawn by the device since powered on: 14.9
 Absent Counter: 0
Over Current Counter: 0
Short Current Counter: 0
Invalid Signature Counter: 0
Power Denied Counter: 0
 
Power Negotiation Used: None
LLDP Power Negotiation       --Sent to PD--      --Rcvd from PD--
Power Type:                  -                    -
Power Source:                -                    -
Power Priority:              -                    -
Requested Power(W):          -                    -
Allocated Power(W):          -                    -
 
Four-Pair PoE Supported: Yes
Spare Pair Power Enabled: No
Four-Pair PD Architecture: N/A
Perpetual POE Enabled: TRUE

This table provides release and related information for the features explained in this module.

These features are available in all the releases subsequent to the one they were introduced in, unless noted otherwise.

Use the Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to Cisco Feature Navigator.