H3C S5120-SI Series Operation Manual page 80

The current device only supports Layer 2 aggregation groups.
States of the member ports in an aggregation group
A member port in an aggregation group can be in one of the following two states:
Selected: a selected port can forward user traffic.
Unselected: an unselected port cannot forward user traffic.
The rate of an aggregate interface is the sum of the selected member ports' rates. The duplex mode of
an aggregate interface is consistent with that of the selected member ports. Note that all selected
member ports use the same duplex mode.
For how the state of a member port is determined, refer to
aggregation mode.
LACP protocol
The Link Aggregation Control Protocol (LACP) is defined in IEEE 802.3ad. It uses link aggregation
control protocol data units (LACPDUs) for information exchange between LACP-enabled devices.
LACP is automatically enabled on interfaces in a dynamic aggregation group. For information about
dynamic aggregation groups, refer to
LACPDUs to notify the remote system (the partner) of its system LACP priority, system MAC address,
LACP port priority, port number, and operational key. Upon receiving an LACPDU, the partner
compares the received information with the information received on other interfaces to determine the
interfaces that can operate as selected interfaces. This allows the two systems to reach an agreement
on which link aggregation member ports should be placed in selected state.
Operational key
When aggregating ports, link aggregation control automatically assigns each port an operational key
based on port rate, duplex mode and link state.
In an aggregation group, all selected ports are assigned the same operational key.
Class-two configurations
The contents of class-two configurations are listed in
different from the aggregate interface in the class-two configurations cannot be a selected port.
Table 1-1 Class-two configurations
Type
Port isolation
VLAN
MAC address learning
Dynamic aggregation
Whether a port has joined an isolation group
Permitted VLAN IDs, default VLAN, link type (trunk, hybrid, or access),
tag mode
MAC address learning capability, MAC address learning limit, forwarding
of frames with unknown destination MAC addresses after the upper limit
of the MAC address table is reached
1-2
Static aggregation mode
mode. An LACP-enabled interface sends
Table 1-1. In an aggregation group, a member port
Considerations
and Dynamic