H3C Technologies H3C S3100 Series Switches - Manual (Page 140)

Operation Manual – Link Aggregation
H3C S3100-52P Ethernet Switch Chapter 1 Link Aggregation Configuration
1-4
II. Port status of static aggregation group
A port in a static aggregation group can be in one of the two states: selected or
unselected. In a static aggregation group, both the selected and the unselected ports
can transceive LACP protocol packets; the selected ports can transceive user service
packets, but the unselected ports cannot.
Note:
In an aggregation group, the selected port with the smallest port number serves as the
master port of the group, and other selected ports serve as member ports of the group.
In a static aggregation group, the system sets the ports to selected or unselected state
by the following rules:
z
The system sets the "most preferred" ports (that is, the ports take most
precedence over other ports) to selected state, and others to unselected state.
Port precedence descends in the following order: full duplex/high speed, full
duplex/low speed, half duplex/high speed, half duplex/low speed.
z
The system sets the state of the following ports to unselected: port connected to a
peer device different from the one the master port is connected to; port connected
to the same peer device as the master port but to a peer port that is not in the
same aggregation group as the peer port of the master port.
z
The system sets the ports unable to aggregate with the master port (due to some
hardware limit, for example, cross-board aggregation unavailability) to unselected
state.
z
The system sets the ports with basic port configuration different from that of the
master port to unselected state.
There is a limit on the number of selected ports in an aggregation group. Therefore, if
the number of the member ports that serves as selected ports in an aggregation group
exceeds the maximum number supported by the device, the system will choose the
ports with lower port numbers as the selected ports, and set others as unselected ports.
1.1.6 Dynamic LACP Aggregation Group
I. Introduction to dynamic LACP aggregation group
A dynamic LACP aggregation group is automatically created and removed by the
system. Users cannot add/remove ports to/from it. A port can participate in dynamic link
aggregation only when it is LACP-enabled. Ports can be aggregated into a dynamic
aggregation group only when they are connected to the same peer device and have the
same basic configuration (such as rate and duplex mode).