H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 130)

16-4
When setting the state of the ports in the local and remote static aggregation groups, the local and
remote systems do the following:
1) Compare their system IDs to identify the higher priority system. (The system ID comprises LACP
priority and system MAC address.)
z
First compare the system LACP priorities. The system with lower system LACP priority wins out.
z
If the system LACP priorities are the same, compare the system MAC addresses. The system with
the smaller MAC address wins out.
2) Compare the port IDs on the higher priority system. (The port ID comprises port LACP priority and
port number.)
z
Compare the port LACP priorities. The port with lower port LACP priority wins out.
z
If two ports with the same port LACP priority are present, compare their port numbers. The one with
the smaller port ID wins out to become the reference port.
3) Select the candidates for selected ports. To be a candidate, a port must be in the up state with the
same speed, duplex mode, link state, and basic configuration as the reference port; in addition,
their peer ports on the other system must have the same configuration. All the ports but the
selected-port candidates become unselected.
4) As there is a limit on the number of selected ports, not all selected-port candidates can become
selected ports. Before the limit is reached, all the candidates are set to the selected state. When
the limit is reached, the candidates with lower port numbers are set to the selected state while the
other candidates are set to the unselected state. At the same time, the other system gets aware of
the state change of the ports on the higher priority system and thus sets the state of the
corresponding local ports.
5) Set the selected port with the lowest port number as the master port in the aggregation group on
each system.
Port configuration considerations in static aggregation
Like in a manual aggregation group, in a static LACP 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 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 static 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.
Load Sharing in a Link Aggregation Group
Link aggregation groups fall into load sharing aggregation groups and non-load sharing aggregation
groups depending on their support to load sharing.
A load sharing aggregation group can contain at least one selected port but a non-load sharing
aggregation group can contain only one.