3Com Switch 7750 Configuration Guide Guide

178 CHAPTER 22: LINK AGGREGATION CONFIGURATION
Operation Key An operation key of an aggregation port is a configuration combination generated
by system depending on the configurations of the port (rate, duplex mode, other
basic configuration, and management key) when the port is aggregated.
1 The selected ports in a manual/static aggregation group must have the same
operation key.
2 The management key of an LACP-enable static aggregation port is equal to its
aggregation group ID.
3 The management key of an LACP-enable dynamic aggregation port is zero by
default.
4 The member ports in a dynamic aggregation group must have the same operation
key.
Manual Aggregation
Group
Introduction to manual aggregation group
A manual aggregation group is manually created. All its member ports are
manually added and can be manually removed (it inhibits the system from
automatically adding/removing ports to/from it). Each manual aggregation group
must contain at least one port. When a manual aggregation group contains only
one port, you cannot remove the port unless you remove the whole aggregation
group.
LACP is disabled on the member ports of manual aggregation groups, and
enabling LACP on such a port will not take effect.
Port status in manual aggregation group
A port in a manual aggregation group can be in one of the two states: selected or
standby. The selected port with the minimum port number serves as the master
port of the group, and other selected ports serve as member ports of the group.
There is a limit on the number of selected ports in an aggregation group.
Therefore, if the number of the member ports that can be set as selected ports in
an aggregation group exceeds the maximum number supported by the device, the
system will choose the ports with lower port numbers as the selected ports, and
set others as standby ports.
Requirements on ports for manual aggregation
Generally, there is no limit on the rate and duplex mode of the ports you want to
add to a manual aggregation group. However, the following cases will be
processed differently:
■ For the ports which are initially down, there is no limit on the rate and duplex
mode of the ports when they are added to an aggregation group;
■ For the currently down ports which used to be up and whose rate and duplex
mode are specified in the negotiation mode or mandatory mode, the rate and
duplex mode of each port must be the same as those of other ports when they
are aggregated;
■ When the rate and duplex mode of a port in the manual aggregation group
change, the system does not deaggregate the aggregation group and all the
ports in the group work normally. However, if the rate of the master port
decreases and the duplex mode of the master port changes, the packets
forwarded on the port may be dropped.