Cisco Sg3008 Manual

							Port Management
Link Aggregation
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However, there are cases when one link partner is temporarily not configured for 
LACP. One example for such case is when the link partner is on a device, which is 
in the process of receiving its configuration using the auto-config protocol. This 
devices ports are not yet configured to LACP. If the LAG link cannot come up, the 
device cannot ever become configured. A similar case occurs with dual-NIC 
network-boot computers (e.g. PXE), which receive their LAG configuration only 
after they bootup.
When several LACP-configured ports are configured, and the link comes up in one 
or more ports but there are no LACP responses from the link partner for those 
ports, the first port that had link up is added to the LACP LAG and becomes active 
(the other ports become non-candidates). In this way, the neighbor device can, for 
example, get its IP Address using DHCP and get its configuration using auto-
configuration.
Setting LACP Parameter Settings
Use the LACP page to configure the candidate ports for the LAG and to configure 
the LACP parameters per port. 
With all factors equal, when the LAG is configured with more candidate ports than 
the maximum number of active ports allowed (8), the device selects ports as 
active from the dynamic LAG on the device that has the highest priority.
NOTEThe LACP setting is irrelevant on ports that are not members of a dynamic LAG.
To  d e f i n e  t h e  L A C P  s e t t i n g s :
STEP 1Click Port Management > Link Aggregation > LACP.
STEP  2Enter the LACP System Priority. See LACP Priority and Rules.
STEP  3Select a port, and click Edit.
STEP  4Enter the values for the following fields:
•Port—Select the port number to which timeout and priority values are 
assigned.
•LACP Port Priority—Enter the LACP priority value for the port. See Setting 
LACP Parameter Settings.
•LACP Timeout—Time interval between the sending and receiving of 
consecutive LACP PDUs. Select the periodic transmissions of LACP PDUs, 
which occur at either a Long or Short transmission speed, depending upon 
the expressed LACP timeout preference. 
						

							Port Management
UDLD
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STEP  5Click Apply. The Running Configuration file is updated.
UDLD
See Port Management: Unidirectional Link Detection.
PoE
See Port Management: PoE.
Configuring Green Ethernet
This section describes the Green Ethernet feature that is designed to save power 
on the device. 
It contains the following sections:
•Green Ethernet Overview
•Setting Global Green Ethernet Properties
•Setting Green Ethernet Properties for Ports
Green Ethernet Overview
Green Ethernet is a common name for a set of features that is designed to be 
environmentally friendly, and to reduce the power consumption of a device. Green 
Ethernet is different from EEE in that green ethernet energy-detect is enabled on 
all devices where only the Gigabyte ports are enable with EEE.
The Green Ethernet feature can reduce overall power usage in the following ways:
•Energy-Detect Mode— On an inactive link, the port moves into inactive 
mode, saving power while keeping the Administrative status of the port Up.  
						

							Port Management
Configuring Green Ethernet
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Recovery from this mode to full operational mode is fast, transparent, and no 
frames are lost. This mode is supported on both GE and FE ports. 
•Short-Reach Mode—This feature provides for power savings on a short 
length of cable. After cable length is analyzed, the power usage is adjusted 
for various cable lengths. If the cable is shorter than 50 meters, the device 
uses less power to send frames over the cable, thus saving energy. This 
mode is only supported on RJ45 GE ports; it does not apply to Combo 
ports.
This mode is globally disabled by default. It cannot be enabled if EEE mode 
is enabled (see below).
In addition to the above Green Ethernet features, the 802.3az Energy Efficient 
Ethernet (EEE) is found on devices supporting GE ports. EEE reduces power 
consumption when there is no traffic on the port. See 802.3az Energy Efficient 
Ethernet Feature for more information (available on GE models only).
EEE is enabled globally by default. On a given port, if EEE is enabled, short reach 
mode be disabled. If Short Reach Mode is enabled, EEE be grayed out. 
These modes are configured per port, without taking into account the LAG 
membership of the ports. 
The device LEDs are power consumers. Since most of the time the devices are in 
an unoccupied room, having these LEDs lit is a waste of energy. The Green 
Ethernet feature enables you to disable the port LEDs (for link, speed, and PoE) 
when they are not required, and to enable the LEDs if they are needed (debugging, 
connecting additional devices etc.).
On the System Summary page, the LEDs that are displayed on the device board 
pictures are not affected by disabling the LEDs.
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. The amount of 
energy saved by EEE is not displayed. 
						

							Port Management
Configuring Green Ethernet
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Power Saving by Disabling Port LEDs
The Disable Port LEDs feature allows the user to save extra power consumed by 
device LEDs. Since most of the time the devices are in an unoccupied room, 
having these LEDs lit is a waste of energy. The Green Ethernet feature enables you 
to disable the port LEDs (for link, speed, and PoE) when they are not required, and 
to enable the LEDs if they are needed (debugging, connecting additional devices 
etc.).
On the System Summary page, the LEDs that are displayed on the device board 
pictures are not affected by disabling the LEDs.
On the Green Ethernet -> Properties page, the device enables the user to disable 
the ports LEDs in order to save power.
802.3az Energy Efficient Ethernet Feature
This section describes the 802.3az Energy Efficient Ethernet (EEE) feature.
It covers 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:  
						

							Port Management
Configuring Green Ethernet
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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 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. 
Both sides of a connection (device port and connecting device) must support 
802.3az EEE for it to work. When traffic is absent, both sides send signals 
indicating that power is about to be reduced. When signals from both sides are 
received, the Keep Alive signal indicates that the ports are in LPI status (and not in 
Down status), and power is reduced.
For ports to stay in LPI mode, the Keep Alive signal must be received continuously 
from both sides.
Adver tise Capabilities Negotiation
802.3az EEE support is advertised during the Auto-Negotiation stage. Auto-
Negotiation provides a linked device with the capability to detect the abilities 
(modes of operation) supported by the device at the other end of the link, 
determine common abilities, and configure itself for joint operation. Auto-
Negotiation is performed at the time of link-up, on command from management, or 
upon detection of a link error. During the link establishment process, both link 
partners to exchange their 802.3az EEE capabilities. Auto-Negotiation functions 
automatically without user interaction when it is enabled on the device.
NOTEIf Auto-Negotiation is not enabled on a port, the EEE is disabled. The 
only exception is if the link speed is 1GB, then EEE still e enabled even though 
Auto-Negotiation is disabled.
Link Level Discovery for 802.3az EEE 
In addition to the capabilities described above, 802.3az EEE capabilities and 
settings are also advertised using frames based on the organizationally-specific 
TLVs defined in Annex G of IEEE Std 802.1AB protocol (LLDP). LLDP is used to 
further optimize 802.3az EEE operation after auto-negotiation is completed. The 
802.3az EEE TLV is used to fine tune system wake-up and refresh durations.
Availability of 802.3az EEE
Please check the release notes for a complete listing of products that support EEE. 
						

							Port Management
Configuring Green Ethernet
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Default Configuration
By default, 802.3az EEE and EEE LLDP are enabled globally and per port.
Interactions Between Features
The following describe 802.3az EEE interactions with other features:
•If auto-negotiation is not enabled on the port, the 802.3az EEE operational 
status is disabled. The exception to this rule is that if the link speed is 
1gigabyte, EEE still be enabled even though Auto-Negotiation is disabled. 
•If 802.3az EEE is enabled and the port is going Up, it commences to work 
immediately in accordance with the maximum wake time value of the port.
•On the GUI, the EEE field for the port is not available when the Short Reach 
Mode option on the port is checked.
•If the port speed on the GE port is changed to 10Mbit, 802.3az EEE is 
disabled. This is supported in GE models only.
802.3az EEE Configuration Workflow
This section describes how to configure the 802.3az EEE feature and view its 
counters.
STEP 1Ensure that auto-negotiation is enabled on the port by opening the Por t 
Management > Port Settings page.
a. Select a port and open the Edit Port Setting page.
b. Select Auto Negotiation field to ensure that it is Enabled.
STEP  2Ensure that 802.3 Energy Efficient Ethernet (EEE) is globally enabled in the Port 
Management > Green Ethernet > Properties page (it is enabled by default). This 
page also displays how much energy has been saved.
STEP  3Ensure that 802.3az EEE is enabled on a port by opening the Green Ethernet > Port 
Settings page. 
a. Select a port, open the Edit Port Setting page.
b. Check the 802.3 Energy Efficient Ethernet (EEE) mode on the port (it is enabled 
by default).
c. Select whether to enable or disable advertisement of 802.3az EEE capabilities 
through LLDP in 802.3 Energy Efficient Ethernet (EEE) LLDP (it is enabled by 
default). 
						

							Port Management
Configuring Green Ethernet
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STEP  4To see 802.3 EEE-related information on the local device, open the 
Administration > Discovery LLDP >LLDP Local Information page, and view the 
information in the 802.3 Energy Efficient Ethernet (EEE) block. 
STEP  5To display 802.3az EEE information on the remote device, open the Administration 
> Discovery LLDP > LLDP Neighbor Information pages, and view the information in 
the 802.3 Energy Efficient Ethernet (EEE) block. 
Setting Global Green Ethernet Properties
The Properties page displays and enables configuration of the Green Ethernet 
mode for the device. It also displays the current power savings. 
To enable Green Ethernet and EEE and view power savings:
STEP 1Click Port Management > Green Ethernet > Properties.
STEP  2Enter the values for the following fields:
•Energy Detect Mode—Disabled by default. Click the checkbox to enable.
•Short Reach—Globally enable or disable Short Reach mode if there are GE 
ports on the device.
NOTEIf Short Reach is enabled, EEE must be disabled.
•Port LEDs—Select to enable the port LEDs. When these are disabled, they 
do not display link status, activity, etc.
•Power Savings—Displays the percentage of power saved by running 
Green Ethernet and Short Reach. The power savings displayed is only 
relevant to the power saved by Short Reach and Energy Detect modes. The 
EEE power savings is dynamic by nature since it is based on port utilization 
and is therefore not taken into consideration. The power saving calculation is 
performed by comparing the maximum power consumption without power 
savings to the current consumption.
•Cumulative Energy Saved—Displays the amount of energy saved from the 
last device reboot. This value is updated each time there is an event that 
affects power saving.
•802.3 Energy Efficient Ethernet (EEE)— Globally enable or disable EEE 
mode.  
						

							Port Management
Configuring Green Ethernet
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STEP  3Click Apply. The Green Ethernet Properties are written to the Running 
Configuration file.
Setting Green Ethernet Properties for Ports 
The Port Settings page displays the current Green Ethernet and EEE modes per 
port, and enables configuring Green Ethernet on a port using the Edit Port Setting 
page. For the Green Ethernet modes to operate on a port, the corresponding 
modes must be activated globally in the Properties page. 
Note that EEE settings are only displayed for devices that have GE ports. EEE 
works only when ports are set to Auto negotiation. The exception is that EEE is still 
functional even when Auto Negotiation is disabled, but the port is at 1GB or higher.
To define per port Green Ethernet settings:
STEP 1Click Port Management > Green Ethernet > Port Settings.
The Port Settings page displays the following:
•Global Parameter Status—Describes the enabled features.
For each port the following fields are described:
•Port—The port number.
•Energy Detect—State of the port regarding Energy Detect mode: 
-Administrative—Displays whether Energy Detect mode was enabled.
-Operational—Displays whether Energy Detect mode is currently 
operating.
-Reason—If Energy Detect mode is not operational, displays the reason.
•Short Reach—State of the port regarding Short Reach mode:
-Administrative—Displays whether Short Reach mode was enabled.
-Operational—Displays whether Short Reach mode is currently 
operating.
-Reason—If Short-Reach mode is not operational, displays the reason.
-Cable Length—Displays VCT-returned cable length in meters. 
						

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Configuring Green Ethernet
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NOTEShort-reach mode is only supported on RJ45 GE ports; it does not 
apply to Combo ports.
•802.3 Energy Efficient Ethernet (EEE)—State of the port regarding the EEE 
feature :
-Administrative—Displays whether EEE was enabled.
-Operational—Displays whether EEE is currently operating on the local 
port. This is a function of whether it has been enabled (Administrative 
Status), whether it has been enabled on the local port and whether it is 
operational on the local port.
-LLDP Administrative—Displays whether advertising EEE counters 
through LLDP was enabled.
-LLDP Operational—Displays whether advertising EEE counters through 
LLDP is currently operating.
-EEE Suppor t on Remote—Displays whether EEE is supported on the link 
partner. EEE must be supported on both the local and remote link 
partners.
NOTEThe window displays the Short Reach, Energy Detect and EEE 
settings for each port; however, they are not enabled on any port unless they 
are also enabled globally by using the Properties page. To enable Short 
Reach and EEE globally, see Setting Global Green Ethernet Properties.
STEP  2Select a Port and click Edit.
STEP  3Select to enable or disable Energy Detect mode on the port. 
STEP  4Select to enable or disable Short Reach mode on the port if there are GE ports on 
the device.
STEP  5Select to enable or disable 802.3 Energy Efficient Ethernet (EEE) mode on the port 
if there are GE ports on the device. 
STEP  6Select to enable or disable 802.3 Energy Efficient Ethernet (EEE) LLDP mode on 
the port (advertisement of EEE capabilities through LLDP) if there are GE ports on 
the device.
STEP  7Click Apply. The Green Ethernet port settings are written to the Running 
Configuration file. 
						

							Port Management
Configuring Green Ethernet
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