3Com SuperStack 4 Configuration Manual page 45

with the minimum port number serves as the master port, while others as
sub-ports.
In a manual aggregation group, the system sets the ports to active or inactive state
by using these rules:
The system sets the port with the highest priority to active state, and others to
■
inactive state based on the following descending order of priority levels:
full duplex/high speed
■
full duplex/low speed
■
half duplex/high speed
■
half duplex/low speed
■
The system sets to inactive state the ports which cannot aggregate with the
■
active port with minimum port number, due to hardware limit, for example,
trans-board aggregation unavailable.
The system sets to inactive state the ports with basic configurations different
■
from that of the active port with minimum port number.
In a static LACP aggregation group, the system sets the ports to active or inactive
state by using these rules:
The system sets the port with the highest priority to active state, and others to
■
inactive state based on the following descending order of priority levels:
full duplex/high speed
■
full duplex/low speed
■
half duplex/high speed
■
half duplex/low speed
■
The system sets to inactive state the ports which connect to different peer
■
devices from one that the active port with minimum port number connects to,
or the ports in different aggregation groups though they are connected to the
same peer device.
The system sets to inactive state the ports which cannot aggregate with the
■
active port with minimum port number, due to hardware limit, for example,
trans-board aggregation unavailable.
The system sets to inactive state the ports with basic configurations different
■
from that of the active port with minimum port number.
Because only a defined number of ports can be supported in an aggregation
group, if the active ports in an aggregation group exceed the port quantity
threshold for that group, the system shall set some ports with smaller port
numbers (in ascending order) as selected ports and others as unselected ports.
Both selected and unselected ports can transceive LACP protocol, but unselected
ports cannot forward user service packets.
Dynamic LACP Aggregation
The LACP uses peer exchanges across the links to determine, on an ongoing basis,
the aggregation capability of the various links, and continuously provides the
maximum level of aggregation capability achievable between a given pair of
Link Aggregation Configuration 57