Table 5
A comparison between static and dynamic aggregation modes
Aggregation
mode
LACP status on
member ports
Pros Cons
Static Disabled
Aggregation is stable. Peers do
not affect the aggregation state of
the member ports.
The member ports do not adjust
the aggregation state according
to that of the peer ports. The
administrator must manually
maintain link aggregations.
Dynamic Enabled
The administrator does not need
to maintain link aggregations. The
peer systems maintain the
aggregation state of the member
ports automatically.
Aggregation is unstable. The
aggregation state of the member
ports is susceptible to network
changes.
The following points apply to a dynamic link aggregation group:
•
A Selected port can receive and send LACPDUs.
•
An Unselected port can receive and send LACPDUs only if it is up and has the same class-two
configurations as the aggregate interface.
Aggregating links in static mode
LACP is disabled on the member ports in a static aggregation group. You must manually maintain the
aggregation state of the member ports.
The static link aggregation procedure comprises:
•
•
Setting the aggregation state of each member port
Selecting a reference port
The system selects a reference port from the member ports that are:
•
Are in the up state and have
•
Have the same class-two configurations as the aggregate interface.
The candidate ports are sorted by duplex and speed in this order: full duplex/high speed, full
duplex/low speed, half duplex/high speed, and half duplex/low speed. The one at the top is selected
as the reference port. If two ports have the same duplex mode and speed, the one with the lower port
number wins.
Setting the aggregation state of each member port
After selecting the reference port, the static aggregation group sets the aggregation state of each
member port.
29
