Static Lacp Link Aggregation - H3C S9500 Series Operation Manual

Operation Manual – Link Aggregation
H3C S9500 Series Routing Switches
Note:
Because changing an aggregation-related configuration setting on a port may cause
the selected-state change of other ports and thus affects services, you are
recommended to do that with caution.

1.2.2 Static LACP link aggregation

I. Overview
You can configure static LACP aggregation by manually assigning ports to a
LACP-enabled aggregation group. As soon as a port is assigned to a static LACP
aggregation group, LACP is enabled on the port.
II. 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. The selected port with the lowest port number is the master port and all others
are member ports.
All member ports that cannot aggregate with the master are placed in unselected state.
These ports include those using the basic configurations different from the master port
or those located on a board different from the master port because of hardware
restriction.
Member ports in up state can be selected if they have the configuration same as that of
the master port. The number of selected ports however, is limited in a static aggregation
group. When the limit is exceeded, the local and remote systems negotiate the state of
their ports as follows:
1) Compare the actor and partner system IDs that each comprises a system LACP
priority plus a system MAC address as follow:
First compare the system LACP priorities. The system with lower system LACP
priority wins out.
If they are the same, compare the system MAC addresses. The system with the
smaller ID has higher priority. (the lower the LACP priority, the smaller the MAC
address, and the smaller the device ID)
2) Compare the port IDs that each comprises a port LACP priority and a port number
on the system with higher ID as follows:
Compare the port LACP priorities. The port with lower port LACP priority wins out.
If two ports with the same port LACP priority are present, compare their port
numbers. The state of the ports with lower IDs then change to selected and the
state of the ports with higher IDs to unselected, so does the state of their
Chapter 1 Link Aggregation Overview
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