3Com Switch 8807, Configuration Manual

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Overview 103
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The system sets to inactive state the ports which cannot be aggregated with
the port, due to hardware limit (for example, trans-module aggregation is
forbidden).
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The system sets to inactive state the ports with basic configurations different
from the active port.
Since only a defined number of ports can be added in an aggregation group, then
if the active ports in an aggregation group exceed the maximum threshold for that
group, the system shall set some ports with smaller port numbers (in ascending
order) as active ports and others as inactive ports. Both active and inactive ports
can transmit and receive LACP protocol, but the inactive ports cannot forward user
service packets.
Dynamic LACP aggregation
The system can create/delete automatically dynamic LACP aggregations, and you
cannot add/delete member ports into/from dynamic LACP aggregation. The
system can also aggregate one port, which is called single port aggregation. The
dynamic LACP aggregation LACP is in enabled state. The system can only
aggregate the ports with the same speed, duplex attribute, device connection,
basic configuration.
Since only a defined number of ports can be added in an aggregation group, then
if the current member ports in an aggregation group exceed the maximum
threshold for that group, the system shall set some ports with smaller device ID
(system pr system MAC address) and smaller port ID (port pr port
number) as active ports, and others as inactive ports. If the maximum threshold is
not exceeded, all member ports are active ports. Both active and inactive ports can
transmit and receive LACP protocol, but the inactive ports cannot forward user
service packets. In an aggregation group, the active port with the minimum port
number serves as the master port, while others as slave ports. When comparing
device ID, the system compare system priority first, and then system MAC address
in the case of the same system priority. The smaller device ID is regarded as higher
priority. When comparing port ID, the system compares port priority first, and then
port number in the case of the same port priority. The smaller port ID is regarded
as higher priority. If the device ID changes to higher priority, the active and inactive
state of the member ports in an aggregation group depends on the device port ID.
You can also set system and port priority to define active and inactive ports.
Load Sharing Types of Load sharing
In terms of load balancing, link aggregation may be load balancing aggregation
and non-load balancing aggregation The 8500 series allocate IP packet load
sharing according to destination and source IP addresses. The switches allocate
non-IP packet load sharing according to source and destination MAC addresses.
You can check protocol types in determining if to use IP or MAC addresses. The
packet with 0800 ETYPE Ethernet field is IP packet. In general, the system only
provides limited resources. The system will always allocate hardware aggregation
resources to the load balancing aggregation groups with higher priority levels.
When the load sharing aggregation resources are used up for existing aggregation
groups, newly-created aggregation groups will be non-load sharing ones. The
priority levels (in descending order) for allocating load sharing aggregation
resources are as follows: