Kingston Technology Kingston Fast EtheRx KNS3250/R - Manual (Page 21)

Kingston Technology Company KNS3250/R User’s Guide - Rev. A00
16 Kingston Switch Configuration Utility
Load Balancing Method
In a multiple link trunk, the links within a trunk should have an equal amount of
trafc in order to achieve maximum efciency. Thus, some sort of load balancing
amongst the links of a trunk must be deployed. The Kingston KNS1650/R, 2450/R,
and 3250/R switches support MAC address based and port based balancing
methods. Using these methods, any packet with a trunk destination received by the
switch can be forwarded to a proper trunk port. After choosing one method, the user
must specify the relative load-balancing mapping to complete the conguration of
the trunk port load balancing.
Trunk Selection, Trunk Port Assignment
Place checkmarks in the boxes of the desired trunk and check the desired trunk port
assignments per trunk.
Trunk: A Trunk is a group of Trunk Ports grouped together.
Port Based Trunk: Each Port Based Trunk may have 2, 3, or 4 Trunk Ports.
MAC Address Based Trunk: Each MAC Address Based Trunk must contain 4
Ports.
Trunk Ports: A port assigned to a Trunk. The Trunk Ports are setup in groups of 4
and must be selected based on the groups. For example, Trunk 1 can only contain
Trunk Ports 1, 2, 3, or 4.
Load Balancing Mapping - MAC Address Based
When the switch receives a packet with a trunk destination, it will automatically
forward the packet to a trunk port based on the source MAC address (SA) and
destination MAC address (DA) of the packet. The device uses two bits from SA
and DA to map to four trunk ports.
The user can select which two bits should be used for mapping:
[1:0]
Uses bit 1 and 0 for mapping.
[3:2] Uses bit 3 and 2 for mapping.
[5:4] Uses bit 5 and 4 for mapping.
[7:6] Uses bit 7 and 6 for mapping.
Each MAC Address contains 6 bytes of data, the last byte is taken from the source
MAC address (SA) and the last byte from the destination MAC address (DA). Each
byte contains 8 bits of data and the user can determine which two bits of the last
byte are used to map the trunk port. See the example on the following page: