Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 138)

NOTE
Layer 2 and Layer 3 AppleTalk traffic is not load-balanced. Layer 3 routed IP or IPX traffic also is not
load balanced. These traffic types will however still be forwarded on the LAG ports.
Support for IPv6 when sharing traffic across a LAG group
Brocade devices that support IPv6 take the IPv6 address for a packet into account when sharing traffic
across a LAG group. The load sharing is performed in the same way it is for IPv4 addresses; that is,
LAG types with a traffic load that is shared based on IPv4 address information can now use IPv6
addresses to make the load sharing decision.
Load balancing for unknown unicast, multicast, and broadcast traffic
Brocade 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 LAG 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 LAG
group.
Note that this does not apply to known unicast traffic, which is always load balanced across all the
ports of a LAG group based on the traffic's Layer 2 and Layer 3 source and destination parameters.
How LAG load sharing works
The load balancing method for bridged traffic varies depending on the traffic type. Load balancing for
routed traffic is always based on the source and destination IP addresses and protocol field (not
applicable for FastIron stackable devices).
LAG Load sharing on FastIron devices TABLE 28
Traffic type Load balancing method
Layer 2 Bridged non-IP Source and destination MAC addresses
Layer 2 Bridged
TCP/UDP Source and destination MAC addresses, source and destination IP addresses, and
source and destination TCP/UDP ports.
Layer 2 Bridged IP
(non-TCP/UDP) Source and destination MAC addresses, and source and destination IP addresses.
Layer 3 Routed traffic Source and destination IP addresses and protocol field.
Layer 2 Bridged IPv4
TCP/UDP Source and destination IP addresses, and source and destination TCP/UDP ports.
Layer 2 Bridged IPv4
Non-TCP/UDP Source and destination IP addresses.
Layer 2 Bridged IPv6
TCP/UDP Source and destination IP addresses, source and destination TCP and UDP ports, and
flow label.
Layer 2 Bridged IPv6
Non-TCP/UDP Source and destination TCP and UDP ports, and flow label.
Layer 3 Routed traffic Source and destination IP addresses and protocol field.
Link Aggregation
138 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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