FTOS Configuration Guide for the C-Series - Force10 Networks

• If the newly PoE-enabled port has a higher priority, then the CLI is accepted, and power is terminated
on the lowest priority port in the chassis. If another power supply is added to the system at a later time,
both ports receive power.
• If all of the lower priority ports combined cannot meet the power requirements of the newly enabled
port, then the CLI is accepted, but power on the lower priority ports is not terminated, and no power is
supplied to the port.
The second result in this scenario is true even if a powered device is not connected to the port. Power can
be allocated to a port, thus subtracting it from the power budget and making it unavailable to other ports,
but that power does not have to be consumed.
Managing Power Priorities
PoE-enabled ports have power access priorities based first on their configuration and then by line card and
port number. The default prioritization is presented in Table 62.
Note: For S-Series, where Table 62 refers to “line cards with the lowest slot number”, substitute “S-Series
stack members with the lowest unit ID”.)
Table 62 PoE Ports Priorities
Configuration Port Number Priority
Ports configured with power inline static Ports with the lowest port numbers in line cards with the
lowest slot number
You can augment the default prioritization using the command [no] power inline priority {critical | high |
low}, where critical is the highest priority, and low is the lowest. FTOS ignores any LLDP-MED priority
on this port if you configure a priority with this command. If you do not configure a port priority with this
command, FTOS honors any LLDP-MED priority.
In general, priority is assigned in this order:
1. power inline [static | auto] setting: power inline static ports have a higher priority than power inline
auto ports
2. power inline priority {critical | high | low} setting or LLDP-MED TLV, if power inline priority is not
configured
3. slot ID
4. port ID
Ports with the lowest port numbers 2
Ports configured with power inline auto Ports with the lowest port numbers in line cards with the
lowest slot number
Ports with the lowest port numbers 4
646 Power over Ethernet
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