H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 201)

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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 attributes, including the port rate, duplex mode and link state configuration.
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 Table 66 . In an aggregation group, a member port
different from the aggregate interface in the class-two configurations cannot be a Selected port.
Table 66 Class-two configurations
Type Considerations
Port isolation
Whether a port has joined an isolation group, and the isolation group to which the
port belongs.
QinQ
QinQ enable state (enable/disable), TPID values in VLAN tags, outer VLAN tags to
be added, inner-to-outer VLAN priority mappings, inner-to-outer VLAN tag mappings,
inner VLAN ID substitution mappings.
VLAN
Permitted VLAN IDs, default VLAN, link type (trunk, hybrid, or access), IP
subnet-based VLAN configuration, protocol-based VLAN configuration, tag mode.
MAC address learning
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.
Some configurations are called class-one configurations. Such configurations, for example, MSTP, can
be configured on aggregate interfaces and member ports but are not considered during operational key
calculation.
The change of a class-two configuration setting may affect the select state of link aggregation member
ports and the ongoing service. To prevent unconsidered change, a message warning of the hazard will
be displayed when you attempt to change a class-two setting, upon which you can decide whether to
continue your change operation.
Link aggregation modes
Depending on the link aggregation procedure, link aggregation operates in one of the following modes:
• Static aggregation mode
• Dynamic aggregation mode
Static aggregation mode
LACP is disabled on the member ports in a static aggregation group. In a static aggregation group, the
system sets a port to Selected or Unselected state by the following rules:
• The system selects a port as the reference port from the ports that are in up state and with the same
class-two configurations as the corresponding aggregate interface. These ports are selected in the
order of full duplex/high speed, full duplex/low speed, half duplex/high speed, and half
duplex/low speed, with full duplex/high speed being the most preferred. If two ports with the same
duplex mode/speed pair are present, the one with the lower port number wins.