H3C S3600V2 SERIES, Layer 2-Lan Switching Configuration Manual

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The IEEE 802.3ad LACP offers basic LACP functions and extended LACP functions, as described
in Table 3 .
Table 3 Basic and extended LACP functions
Category Description
Basic LACP
functions
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 the preceding
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 the Selected state.
Extended LACP
functions
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. The S3600V2 Switch Series can participate in LACP MAD as
either an IRF member switch or an intermediate device.
For more information about IRF, member switches, intermediate devices, and the LACP MAD mechanism,
see IRF Configuration Guide .
2.
LACP priorities
LACP priorities have the following types: system LACP priority and port aggregation priority.
Table 4 LACP priorities
Type Description Remarks
System LACP
priority
Used by two peer devices (or systems) to determine which one is
superior in link aggregation.
In dynamic link aggregation, the system that has higher system LACP
priority sets the Selected state of member ports on its side first, and then
the system that has lower priority sets the port state accordingly.
The smaller the
priority value,
the higher the
priority.
Port aggregation
priority Determines the likelihood of a member port to be selected on a system.
The higher the port aggregation priority, the higher the likelihood.
3.
LACP timeout interval
The LACP timeout interval specifies how long a member port waits to receive LACPDUs from the
peer port. If a local member port fails to receive LACPDUs from the peer within three times the
LACP timeout interval, the member port assumes that the peer port has failed. You can configure
the LACP timeout interval as either the short timeout interval (1 second) or the long timeout interval
(30 seconds).
Link aggregation modes
Link aggregation has the following modes: dynamic and static. Dynamic link aggregation uses LACP
and static link aggregation does not. Table 5 compares the two aggregation modes.