Managing Power-over-Ethernet Devices
Configuring PoE Properties
Cisco Small Business 300 Series Managed Switch Administration Guide  103
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You can decide the following: 
• Maximum power a PSE is allowed to supply to a PD
• During device operation, to change the mode from Class Power Limit to 
Port Limit and vice versa. The power values per port that were configured 
for the Port Limit mode are retained.
• Maximum port limit allowed as a per-port numerical limit in mW (Port Limit 
mode).
• To generate a trap when a PD tries to consume too much and at what 
percent of the maximum power this trap is generated.
The PoE-specific hardware automatically detects the PD class and its power limit 
according to the class of the device connected to each specific port (Class Limit 
mode).
If at any time during the connectivity an attached PD requires more power from the 
switch than the configured allocation allows (no matter if the switch is in Class 
Limit or Port Limit mode), the switch does the following:
• Maintains the up/down status of the PoE port link
• Turns off power delivery to the PoE port
• Logs the reason for turning off power
• Generates an SNMP trap
Configuring PoE Properties
The 
PoE Properties Page 
enables selecting either the Port Limit or Class Limit PoE 
mode and specifying the PoE traps to be generated. 
These settings are entered in advance. When the PD actually connects and is 
consuming power, it might consume much less than the maximum power allowed. 
Output power is disabled during power-on reboot, initialization, and system 
configuration to ensure that PDs are not damaged.