How to Change the PoE Setting on Cisco Catalyst C9300-24U Switch
Selene Gong
Power over Ethernet (PoE) is a critical feature in modern enterprise access switches like the Cisco Catalyst 9300-24U. Whether you're deploying IP phones, wireless access points, or IoT devices, configuring PoE correctly ensures stable performance, power efficiency, and long-term reliability. This guide walks you through how to view, adjust, and troubleshoot PoE settings on the C9300-24U using Cisco IOS XE CLI commands.
What Is the Default PoE Setting on Cisco C9300-24U?
By default, the Catalyst 9300-24U switch supports PoE+ (802.3at) and UPOE (Universal Power over Ethernet) with automatic power negotiation. The switch dynamically allocates power per port based on the connected device’s requirements, ensuring plug-and-play compatibility.
How to View Current PoE Status
To check real-time PoE status per interface, use:
show power inline
For detailed power information, including consumption and status:
show power inline detail
This reveals how much power each port is using and flags any faults or shutdowns due to power limits.
How to Change PoE Settings on a Specific Port
Step-by-Step CLI Configuration
1. Enter Global Configuration Mode:
enable
configure terminal
2. Select the Interface:
interface GigabitEthernet1/0/1
3. Adjust PoE Behavior:
Disable PoE on the port:
power inline never
Enable PoE with auto detection (default):
power inline auto
Set a static power limit (in milliwatts):
power inline static max 15000
Example: 15000 mW = 15W
4. Save the Configuration:
end
write memory
How to Set a Global Power Limit
If you're supporting many high-power devices (like PTZ cameras or access points), you may want to set a global per-port maximum:
power inline port max 30000
This helps enforce limits across all interfaces to avoid power budget exhaustion.
Troubleshooting Common PoE Issues
Use these commands to diagnose faults:
Check inline policing and faults:
show power inline police
View related system logs:
show logging | include POWER
Verify switch power supply and redundancy:
show environment power
Common Issues:
Total switch PoE budget exceeded
Faulty or non-standard connected devices
Inadequate power supply wattage
PoE Configuration Quick Reference
Command
Description
show power inline
Display PoE status on all ports
power inline auto
Enable PoE with automatic negotiation
power inline never
Disable PoE on the interface
power inline static
Enable static power allocation
power inline static max
Set a max power value per port (mW)
show environment power
Check power supply module status
FAQs
Q1: How much PoE power does the C9300-24U support?
A: Up to 960W with dual power supplies, depending on the PSU model.
Q2: Can I use PoE and non-PoE devices together?
A: Yes. Only PoE-enabled ports and connected devices draw power.
Q3: What happens if the power budget is exceeded?
A: Lower-priority ports may be disabled or denied power.
Q4: Is UPOE enabled by default?
A: It varies by SKU. Run show power inline to confirm per port.
Q5: How do I reset PoE settings to default?
A: Use no power inline under the interface to revert to default behavior.
