H3C SR8800 Configuration Manual page 79

NOTE:
Class-two configurations made on an aggregate interface are automatically synchronized to all its
•
member ports. These configurations are retained on the member ports even after the aggregate
interface is removed.
Any class-two configuration change may affect the aggregation state of link aggregation member ports
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and ongoing traffic. To make sure that you are aware of the risk, the system displays a warning message
every time you attempt to change a class-two configuration setting on a member port.
Class-one configurations do not affect the aggregation state of the member port even if they are
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different from those on the aggregate interface. GVRP and MSTP settings are examples of class-one
configurations.
NOTE:
The class-one configuration for a member port is effective only when the member port leaves the
aggregation group.
Reference port
When setting the aggregation state of the ports in an aggregation group, the system automatically picks
a member port as the reference port. A Selected port must have the same port attributes and class-two
configurations as the reference port.
LACP
The IEEE 802.3ad Link Aggregation Control Protocol (LACP) enables dynamic aggregation of physical
links. It uses link aggregation control protocol data units (LACPDUs) for exchanging aggregation
information between LACP-enabled devices.
LACP functions
1.
The IEEE 802.3ad LACP offers basic LACP functions and extended LACP functions, as described
in Table
Table 9 Basic and extended LACP functions
Category
Basic LACP functions
Extended LACP
functions
NOTE:
The SR8800 routers do not support IRF.
9.
Description
Implemented through the basic LACPDU fields, including the system LACP priority,
system MAC address, port aggregation priority, port number, and operational key.
Each member port in a LACP-enabled aggregation group exchanges information
with its peer. When a member port receives an LACPDU, it compares the received
information with the information received on the other member ports. In this way the
two systems reach an agreement on which ports should be placed in Selected state.
Implemented by extending the LACPDU with new Type/Length/Value (TLV) fields.
This is how the LACP multi-active detection (MAD) mechanism of the Intelligent
Resilient Framework (IRF) feature is implemented.
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If a device supports both LACP extensions and IRF, it can participate in LACP
MAD either as an IRF member device or an intermediate device.
•
If a device supports LACP extensions but not IRF, it can participate in LACP MAD
only as an intermediate device.
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