Cisco 550X Series Quick Start Manual page 7

Consider the following when connecting switches capable of
C
AUTION
supplying PoE:
The PoE models of the switches are PSE (Power Sourcing
Equipment) that are capable of supplying DC power to
attaching PD (Powered Devices). These devices include VoIP
phones, IP cameras, and wireless access points. The PoE
switches can detect and supply power to pre-standard
legacy PoE Powered Devices. Due to the support of legacy
PoE, it is possible that a PoE switch acting as a PSE may
mistakenly detect and supply power to an attaching PSE,
including other PoE switches, as a legacy PD.
Even though PoE switches are PSE, and as such should be
powered by AC, they could be powered up as a legacy PD
by another PSE due to false detection. When this happens,
the PoE switch may not operate properly and may not be
able to properly supply power to its attaching PDs.
To prevent false detection, you should disable PoE on the
ports on the PoE switches that are used to connect to PSEs.
You should also first power up a PSE device before
connecting it to a PoE switch. When a device is being falsely
detected as a PD, you should disconnect the device from the
PoE port and power recycle the device with AC power
before reconnecting its PoE ports.
Configuring the Cisco 550X Series
1 2 4
Stackable Managed Switches
Before You Begin
The switch can be accessed and managed by two different methods; over
your IP network using the web-based interface, or by using the switch's
command-line interface through the console port. Using the console port
requires advanced user skills.
Cisco 550X Series Stackable Managed Switches Quick Start Guide 7