Load Sharing; Configuring Link Aggregation - 3Com Switch 7700 Configuration Manual

38 C 2: P C
HAPTER ORT ONFIGURATION

Load Sharing

Configuring Link
Aggregation
compares port priority values and then port numbers and the small port ID is
considered prior. If system ID changes from non-priority to priority, then the
selected or standby state is determined by the port priority of the system. You can
decide whether the port is selected or standby by setting system priority and port
priority.
In terms of load balancing, link aggregation may be load balancing and non-load
balancing. In general, the system only provides limited load balancing aggregation
resources, so the system need to rationally allocate these resources among manual
aggregation groups, static LACP aggregation groups, dynamic LACP aggregation
groups and the aggregation groups including special ports which require hardware
aggregation resources. The system will always allocate hardware aggregation
resources to the 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:
Aggregation groups including special ports which require hardware
■
aggregation resources
Manual and static LACP aggregation groups
■
Aggregation groups that probably reach the maximum rate after the resources
■
are allocated to them
Aggregation groups with the minimum master port numbers if they reach the
■
equal rate with other groups after the resources are allocated to them
When aggregation groups of higher priority levels appear, the aggregation groups
of lower priority levels release their hardware resources. For single-port
aggregation groups, if they can transceive packets normally without occupying
hardware resources, they shall not occupy the resources.
A load sharing aggregation group may contain several selected ports, but a
non-load sharing aggregation group can only have one selected port, while others
as standby ports. Selection criteria of selected ports vary for different types of
aggregation groups.
The Switch 7700 only supports LACP for ports on the same I/O module. A
maximum number of 16 ports can be active in a link aggregation. For modules
that have fewer than 16 ports, such as the 8-port 1000BASE-X-GE module, only
eight ports can be active members of a link aggregation.
Link aggregation configuration includes tasks described in the following sections:
Enabling or Disabling LACP at a Port
■
Creating or Deleting an Aggregation Group
■
Adding or Deleting Ethernet Ports to or from an Aggregation Group
■
Setting or Deleting an Aggregation Group Descriptor
■
Configuring System Priority
■
Configuring Port Priority
■