3Com S7906E - Switch, Configuration Manual

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Configuring the Working Mode of LPUs
Introduction to the Working Mode of LPUs
The S7900E series Ethernet switches support multiple types of LPUs, each of which provides different
MAC address table and routing table. If you need to extend the MAC address table or the routing table,
you can purchase EA, EB, or SD LPUs, that is, the LPUs with the last two letters of the LPU model being
EA, EB, or SD, LSQ1GP12EA for example.
An EA LPU can work in either of the two modes: MAC extension ( bridging ) and route extension
( routing ).
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MAC extension mode: The LPU can provide a 128K MAC address table. It is recommended to use
this mode in a Layer 2 network with a large MAC address table.
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Route extension mode: The LPU can provide a 128K routing table. It is recommended to use this
mode in a Layer 3 network with a large routing table.
An EB or SD LPU can work in either of the four modes: MAC extension ( bridging ), route extension
( routing ), mixed extension ( mix-bridging-routing ), and normal ( normal ).
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MAC extension mode: The EB LPU can provide a 512K MAC address table, and the SD LPU can
provide a 128K MAC address table. It is recommended to use this mode in a Layer 2 network with
a large MAC address table.
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Route extension mode: The EB LPU can provide a 256K routing table, and the SD LPU can provide
128K routing table. It is recommended to use this mode in a Layer 3 network with a large routing
table.
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Mixed extension mode: The EB LPU can provide 258K MAC address table and 258K routing table;
the SD LPU can provide 64K MAC address table and 64K routing table. It is recommended to use
this mode in a network with both a large MAC address table and a large routing table.
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Normal mode: Both the EB LPU and the SD LPU can provide MAC address table and routing table
with their default capacities without any expansion. It is recommended to use this mode in a
network without expansion requirements to both MAC address and routing tables.
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The S7900E series Ethernet switches support multiple types of LPUs, where only EA, EB, and SD
LPUs support working mode configuration.
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After the MAC address table or the routing table is extended, the default capacity of the MAC
address table or the routing table does not take effect any more.
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The working mode configuration of an LPU does not affect the service processing capability of the
whole switch, but that of the LPU only.
Configuring the Working Mode of an EA LPU
Follow these steps to configure the working mode of an EA LPU: