Cisco 350 Series Administration Manual page 243

10
NOTE
196
For ports to stay in LPI mode, the Keep Alive signal must be received continuously from both
sides.
Advertise 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.
If Auto-Negotiation is not enabled on a port, the EEE is disabled. The only exception is if the
link speed is 1GB or 10G, then EEE still e enabled even though Auto-Negotiation is disabled.
Link Level Discovery for
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 see the release notes for a complete listing of products that support EEE.
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 1 gigabyte, 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.
• 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
Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4
Port Management
Green Ethernet