Trunk Group Load Sharing - Foundry Networks FESX Manual

Foundry Configuration Guide for the FESX, FSX, and FWSX
Figure 10.4 shows examples of two Chassis devices connected by multi-slot trunk groups.
Figure 10.4 Examples of multi-slot trunk groups
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Trunk Group Load Sharing

Unlike the FES and other Foundry devices, trunk groups on the FESX, FSX, and FWSX devices are not classified
as switch trunk groups or server trunk groups.
The Foundry device load shares 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 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 trunk ports.
Note Regarding IPv6
Foundry devices that support IPv6 take a packet's IPv6 address 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 whose traffic
load is shared based on IPv4 address information can now use IPv6 addresses to make the load sharing decision.
Load sharing occurs as described in Table 10.4 or Table 10.3.
How Trunk Load Sharing Works
Load balancing procedures differ depending on the software version your device is running. In releases prior to
02.2.00 for the FESX/FWSX, and release 02.1.00 for the FSX, the Foundry 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.
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© Foundry Networks, Inc.
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December 2005