Aggregation Mode - HP J9079A Management And Configuration Manual

Aggregation Mode

When incoming data frames are fowarded by the switch over a trunk, the
switch must determine which port link in the trunk to use for each outgoing
frame. To maintain the frame sequence for traffic flows between devices in
the network, the switch also needs to ensure that frames in each
"conversation" are mapped to the same trunk link. In order to meet this
requirement and to distribute a balanced load across all links in a trunk, the
switch uses an algorithm based on the frame source or destination addresses
to calculate an output link member in the trunk. However, depending on the
device to which a trunk is connected and the traffic flows in the network, this
load-balance algorithm may result in traffic being distributed mostly to one
port in a trunk.
To ensure that the switch traffic load is distributed evenly across all links in
a trunk, the source or destination addresses used in the load-balance
calculation can be selected to provide the best result for trunk connections.
The switch provides six load-balancing modes that apply for both static and
dynamic trunks:
SMAC: All traffic with the same source MAC address is output on the same
■
link in a trunk. This mode works best for switch-to-switch trunk links
where traffic through the switch is received from many different hosts.
■ DMAC: All traffic with the same destination MAC address is output on the
same link in a trunk. This mode works best for switch-to-switch trunk
links where traffic through the switch is destined for many different hosts.
Do not use this mode for switch-to-router trunk links where the destina-
tion MAC address is the same for all traffic.
■ SMAC XOR DMAC: The four least significant bits of the source and
destination MAC addresses in a frame are used to determine the output
link in the trunk. This mode works best for switch-to-switch trunk links
where traffic through the switch is received from and destined for many
different hosts. (This mode is the default setting.)
■ SMAC XOR DMAC XOR IP-Info: The source and destination MAC
addresses and IP information in a frame are used to determine the output
link in the trunk. This mode works best for switch-to-switch trunk links
where traffic through the switch is received from and destined for many
different hosts.
■ Pseudo-randomized: The output link in the trunk is randomly selected.
This mode is useful for networks where frame ordering within conversa-
tions can be neglected and where a high utilization of aggregated links is
important.
Using the ProCurve Web Browser Interface
Web Configuration
2-17