H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 129)

16-3
Port states in a manual aggregation
In a manual aggregation group, ports are either selected or unselected. Selected ports can receive and
transmit data frames whereas unselected ones cannot.
When setting the state of ports in a manual aggregation group, the system considers the following:
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The system selects the port with the highest priority in the up state as the reference port of the
aggregation group. Port priority descends in the following order: full duplex/high speed, full
duplex/low speed, half duplex/high speed, and half duplex/low speed. If multiple ports are of the
same priority, the one with the lowest port number is the reference port.
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Ports in the up state with the same speed, duplex mode, link state, and basic configuration as the
reference port become the candidates for selected ports, while the other ports become unselected
ports.
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There is a limit on the number of selected ports in a manual aggregation group. If the number of
selected-port candidates does not reach the limit, all the candidates become selected ports; if the
number of candidates exceeds the limit, the candidates with lower port numbers become selected
ports, while the other candidates become unselected ports.
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The selected port with the lowest port number serves as the master port of the aggregation group,
and the other ports serve as the member ports of the aggregation group.
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If all the ports of an aggregations port are down, the port with the lowest port number is the master
port. In this case, all of them are unselected ports.
In addition, unless the master port should be selected, a port that joins the group after the limit is
reached will not be placed in selected state even if it should be in normal cases. This is to prevent the
ongoing service on selected ports from being interrupted. You need to avoid the situation however as
the selected/unselected state of a port may become different after a reboot.
Port Configuration Considerations in manual aggregation
As mentioned above, in a manual aggregation group, only ports with configurations consistent with
those of the reference port can become selected. These configurations include port rate, duplex mode,
link state, and other basic configurations, as described in
Consistency Considerations for Ports in an
Aggregation .
You need to maintain the basic configurations of these ports manually to ensure consistency. As one
configuration change may involve multiple ports, this can become troublesome if you need to do that
port by port. As a solution, you may add the ports into an aggregation port group where you can make
configuration for all member ports.
When the configuration of some port in a manual aggregation group changes, the system does not
remove the aggregation; instead, it re-sets the selected/unselected state of the member ports and
re-selects a master port.
Static LACP link aggregation
Overview
Static aggregations are created manually. After you add a port to a static aggregation, LACP is enabled
on it automatically.
Port states in static aggregation
In a static aggregation group, ports can be selected or unselected, where both can receive and transmit
LACPDUs but only selected ports can receive and transmit data frames.