FTOS Configuration Guide for the C-Series - Force10 Networks

• If the device advertises its power requirement through LLDP-MED, then FTOS allocates the
required amount and returns the remaining amount to the budget.
Note: LLDP-MED TLVs are only honored if the port is configured with power inline auto (with or without
the max_milli-watts option).
2. When you configure a port with power inline auto with the power limit option (max_milli-watts),
power is only allocated after you connect a device to the port.
• If the maximum power for the device class is less than the power limit you specified, FTOS
allocates the required amount and returns the remaining amount to the budget.
• If there is not enough power in the budget, the configuration is maintained and the port waits
for power to become available.
• If the maximum power for the device class is more than than the power limit you specified,
FTOS does not allocate any power.
Note: When a port is configured with power inline auto (with or without the max_milli-watts option) and
the PoE device is disconnected, the allocated power is returned to the power budget.
3. When you configure a port with power inline static without the power limit option (max_milli-watts),
FTOS allocates 15.4W (subject to availability and priority) to the port whether or not a device is
connected.
4. When you configure a port with power inline static with the power limit option (max_milli-watts),
FTOS allocates the specified number of Watts.
• If there is not enough power in the budget, the configuration is maintained and port waits for
power to become available.
• If the maximum power for the device class is more than than the power limit you specified,
FTOS does not allocate any power.
Monitoring the Power Budget
The power budget is the amount of power available from the installed PSUs minus the power required to
operate the chassis. Use the show power inline (Figure 451 on page 643) and show power detail
(Figure 452 on page 644) commands to help you determine if power is available for additional PoE ports
(1478.40 Watts are supplied per C-Series PSU; max of 790W on S-Series with load-sharing external DC
PSU).
Enabling PoE on more ports than is supported by the power budget produces one of these results:
• If the newly PoE-enabled port has a lower priority, then the command is accepted, but power is not
allocated to the port. In this case, the following message is displayed.
Message 27 Insufficient Power to Enable PoE
%Warning: Insufficient power to enable. POE oper-status set to OFF for port
FTOS Configuration Guide, version 7.7.1.0 645