Trunk group load sharing, How trunk load sharing works – Brocade TurboIron 24X Series Configuration Guide User Manual
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Brocade TurboIron 24X Series Configuration Guide
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Trunk group overview
Trunk group load sharing
Trunk groups on the devices are not classified as switch trunk groups or server trunk groups.
Devices load-share across the ports in the trunk group. The method used for the load sharing
depends on the following:
•
Device type – Chassis device or Stackable device
•
Traffic type – Layer 2 or Layer 3
•
Software version your device is running
NOTE
Layer 3 routed IP is not load balanced. This traffic types will however still be forwarded on the
trunk ports.
Note regarding IPv6
Devices that support IPv6 take a the IPv6 address for a packet into account when sharing traffic
across a trunk group. The load sharing is performed in the same way it is for IPv4 addresses; that
is; trunk types for which traffic load is shared based on IPv4 address information can now use IPv6
addresses to make the load sharing decision.
Load sharing for unknown unicast, multicast, and broadcast traffic
Devices load balance unknown unicast, multicast, and broadcast traffic based on the source port
and VLAN ID and not on any source or destination information in the packet.
For example, when the switch receives unknown unicast, multicast, and broadcast packets, and
the packets are from the same source port, the packets are forwarded to the same port of the
trunk group. Conversely, when the switch receives unknown unicast, multicast, and broadcast
packets, and the packets are from different source ports, the packets are load-balanced across all
the ports of the trunk group.
Note that this does not apply to known unicast traffic, which is always load balanced across all the
ports of a trunk group based on the traffic's Layer 2 and Layer 3 source and destination
parameters.
How trunk load sharing works
Load balancing procedures differ depending on the software version your device is running. In
earlier releases, the device load balances all bridged traffic based on source and destination MAC
addresses. In subsequent releases, the load balancing method for bridged traffic varies depending
on the traffic type.
NOTE
There is no change in load balancing for routed traffic, which is always based on the source and
destination IP addresses and protocol field .
NOTE
Load balancing is hardware-based.