Cisco SF200-24 Administration Manual page 104

Port Management
Configuring Green Ethernet
Cisco Small Business 200 1. 1 Series Smart Switch Administration Guide
These modes are configured per port, without taking into account the LAG
membership of the ports.
Power savings, current power consumption and cumulative energy saved can be
monitored. The total amount of saved energy can be viewed as a percentage of
the power that would have been consumed by the physical interfaces had they
not been running in Green Ethernet mode. The saved energy displayed is only
related to Green Ethernet. EEE energy saved is not displayed.
802.3az Energy Efficient Ethernet Feature
This section describes the 802.3az Energy Efficient Ethernet (EEE) feature.
It contains the following topics:
• 802.3az EEE Overview
• Advertise Capabilities Negotiation
• Link Level Discovery for 802.3az EEE
• Availability of 802.3az EEE
• Default Configuration
• Interactions Between Features
• 802.3az EEE Configuration Workflow
802.3az EEE Overview
802.3az EEE is designed to save power when there is no traffic on the link. In
Green Ethernet, power is reduced when the port is down. With 802.3az EEE,
power is reduced when the port is up, but there is no traffic on it.
802.3az EEE is only supported on devices with GE ports.
When using 802.3az EEE, systems on both sides of the link can disable portions of
their functionality and save power during periods of no traffic.
802.3az EEE supports IEEE 802.3 MAC operation at 100 Mbps and 1000 Mbps:
LLDP is used to select the optimal set of parameters for both devices. If LLDP is
not supported by the link partner, or is disabled, 802.3az EEE will still be
operational, but it might not be in the optimal operational mode.
The 802.3az EEE feature is implemented using a port mode called Low Power Idle
(LPI) mode. When there is no traffic and this feature is enabled on the port, the port
is placed in the LPI mode, which reduces power consumption dramatically.
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