Lag Hashing Algorithm; Dynamic Lag Limits - Fujitsu PSWITCH 2048T User Manual

FUJITSU PSWITCH
Statistics
Statistics are maintained for all LAG interfaces.

3.1.2.5.4. LAG Hashing Algorithm

The purpose of link aggregation is to increase bandwidth between two switches. It
is achieved by aggregating multiple ports in one logical group. A common problem
of port channels is the possibility of changing packets order in particular TCP
session. The resolution of this problem is correct selection of physical port within
port channel for transmitting the packet to keep original packets order.
To perform this selection, a hash function is used. This function can take several
packet fields as input, and produce a specific destination port number within a port
channel as output. It is possible to use several hashing functions to improve
bandwidth usage efficiently.
The hashing algorithm is configurable for each LAG. The types of LAG algorithms
available may vary depending upon platform capabilities. Typically, an
administrator is able to choose from hash algorithms utilizing the following
attributes of a packet to determine the outgoing port:
 Source MAC, VLAN, EtherType, and incoming port associated with the packet.
 Source IP and Source TCP/UDP fields of the packet.
 Destination MAC, VLAN, EtherType, and incoming port associated with the
packet.
 Destination IP and Destination TCP/UDP Port fields of the packet.
 Source/Destination MAC, VLAN, EtherType, and incoming port associated with
the packet.
 Source/Destination IP and Source/Destination TCP/UDP Port fields of the packet.

3.1.2.5.5. Dynamic LAG Limits

The Dynamic LAG Limits feature allows you to make the number of dynamic ports
the limiting factor, rather than number of dynamic LAG interfaces. The maximum
number of dynamic ports per LAG is as many LAGs as the user wants to create. In
other words, instead of having a limit for 8 dynamic LAGs with eight ports each,
there is a restriction for (8 × 8 = 64) ports that can be configured as members of a
dynamic LAG, and the user can choose to configure 8 × 8, 32 × 2, or any other
combination.
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User's Guide
December/2018