Operation Manual – Link Aggregation
H3C S3610&S5510 Series Ethernet Switches Chapter 1 Link Aggregation Overview
1-5
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.
III. 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.
1.3 Load Sharing in a Link Aggregation Group
A link aggregation group can be load sharing or non-load sharing, depending on the
availability of aggregation resources when the group is created.
z When aggregation resources are available, the group is a load sharing
aggregation group if it contains selected port(s).
z If all aggregation resources are used up, the group is a non-load sharing
aggregation group.
With load sharing enabled, traffic is distributed on the selected ports in the aggregation
group. However, the way of selecting forwarding ports varies by packet type: