Interface and Hardware Components Configuration Guide, Cisco IOS XE 17.18.x (Catalyst 9300 Switches) - Configuring Power over Ethernet

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9300/software/release/17-18/configuration_guide/int_hw/b_1718_int_and_hw_9300_cg/configuring_poe.html

Published

2025-08-08

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

Cisco copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• On Catalyst 9300, the global command hw-module switch <n> upoe-plus enables 802.3bt mode and power-cycles the switch, and in that mode Cisco UPOE switches act as 802.3bt Type 3 devices supporting up to Class 6 on every port. in context
• On Catalyst 9300 the default PoE power management mode is auto: the port detects whether the device needs power and grants it first come, first served if the budget allows. in context
• When the PoE budget cannot cover a request, a Catalyst 9300 denies power, makes sure the port is unpowered, logs a syslog message and updates the LEDs. in context
• After a Catalyst 9300 powers a port from the IEEE class, it uses CDP to learn the Cisco powered device's actual power need and adjusts the power budget to match. in context
• Cisco's Catalyst 9300 IEEE power classification table gives the maximum power per class as: Class 0 15.4 W, Class 1 4 W, Class 2 7 W, Class 3 15.4 W, Class 4 30 W, Class 5 45 W, Class 6 60 W, Class 7 75 W, Class 8 90 W. in context
• On Catalyst 9300, real-time PoE policing acts when a powered device draws more than its allocated maximum, either by error-disabling the port or by logging a warning. in context
• On Catalyst 9300, PoE static mode reserves power for the port even when no powered device is connected. in context
• The Catalyst 9300 guide says PoE+ powered devices use IEEE 802.3at and LLDP power-via-MDI TLVs to negotiate up to 30 W. in context
• For Cisco UPOE (up to 60 W over signal and spare pairs), a Catalyst 9300 enables spare-pair power only after the port and device identify each other as UPOE-capable over CDP or LLDP and the device asks for spare-pair power. in context
• Cisco UPOE+ on Catalyst 9300 follows IEEE 802.3bt, stays compatible with 802.3af, 802.3at and Cisco UPOE, and delivers up to 90 W to 802.3bt Type 4 devices. in context
• Inference: turning on 802.3bt mode on an in-service Catalyst 9300 needs a maintenance window, because the command power-cycles the switch and so drops every PoE phone connected to it. inferred in context

Cite this source record

APA

WarmTransfer. (2025, August 8). Interface and Hardware Components Configuration Guide, Cisco IOS XE 17.18.x (Catalyst 9300 Switches) - Configuring Power over Ethernet. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cat9300-1718-poe

BibTeX

@misc{warmtransfer-cisco-cat9300-1718-poe,
  title  = {Interface and Hardware Components Configuration Guide, Cisco IOS XE 17.18.x (Catalyst 9300 Switches) - Configuring Power over Ethernet},
  author = {{WarmTransfer}},
  year   = {2025},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cat9300-1718-poe},
  note   = {Cisco Systems, accessed 2026-09-24}
}