Cabletron Systems SmartSTACK 10 ELS10-26, User Manual

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Introduction
If a packet’s address is not already stored in the Bridge Address
Table, the SmartSTACK 10 ELS10-26 adds the learned address,
associated segment number, and a timer value indicating the age
of the observation. Consequently, the SmartSTACK 10 ELS10-26
knows the address and associated segment number the next time it
sees that address. By using the information stored in the Bridge
Address Table, the SmartSTACK 10 ELS10-26 is able to quickly
forward each packet to the correct LAN segment.
The SmartSTACK 10 ELS10-26 learns addresses from all packets,
including data transmissions and “keep alive” packets (packets
sent by an idle station to let other stations know it is present and
functional). When devices are added to the network, removed
from it, or relocated, you do not have to reconfigure the
SmartSTACK 10 ELS10-26. The unit automatically learns new
device addresses, recognizes when a previously used address is
missing, or when a device has been moved to a new LAN segment.
An address stored in the Bridge Address Table is discarded if there
is no subsequent activity from that address after a configured
length of time (five minutes by default). This aging process ensures
that the Bridge Address Table is continually updated.
Addresses are continually added to and deleted from the Bridge
Address Table, reflecting the dynamic nature of internetwork
traffic.
Each dynamic entry includes:
• An Ethernet MAC address
• A single port number of the LAN on which the address resides
• The age of the entry
The SmartSTACK 10 ELS10-26 stores 979 dynamic (learned) entries
in its Bridge Address Table.