User guide

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LGORITHMS
Load sharing algorithms allow you to select the distribution technique used by the
load-sharing group to determine the output port selection. Algorithm selection is not
intended for use in predictive traffic engineering.
You can configure one of three load-sharing algorithms on the switch, as follows:
• Port-based — Uses the ingress port to determine which physical port in the
load-sharing group is used to forward traffic out of the switch.
• Address-based — Uses addressing information to determine which physical port in
the load-sharing group to use for forwarding traffic out of the switch. Addressing
information is based on the packet protocol, as follows:
— IP packets — Uses the source and destination MAC and IP addresses, and the
TCP port number.
— IPX packets — Uses the source and destination MAC address, and IPX network
identifiers.
— All other packets — Uses the source and destination MAC address.
• Round-robin — When the switch receives a stream of packets, it forwards one packet
out of each physical port in the load-sharing group using a round-robin scheme.
Using the round-robin algorithm, packet sequencing between clients is not
guaranteed.
If you do not explicitly select an algorithm, the port-based scheme is used. However,
the address-based algorithm has a more even distribution and is the recommended
choice.
The address-based and round-robin load sharing algorithms are supported by Summit
switch products that use the “i” chipset, such as the Summit7i switch. For more
information on the “i” chipset products, refer to Chapter 1.
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ONFIGURING
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To set up the Summit switch to load share among ports, you must create a load-sharing
group of ports. The first port in the load-sharing group is configured to be the “master”
logical port. This is the reference port used in configuration commands. It can be
thought of as the logical port representing the entire port group.