Cabletron Systems SmartSTACK ELS100-S24TX2M, Management Manual, Page: 87 / 102

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Spanning Tree Concepts 87
Spanning Tree Protocol Parameters
Several configuration parameters control the operation of the Spanning
Tree Protocol. Table A-1 describes the parameters and lists the
ELS100-S24TX2M switch default settings for each parameter.
Table A-1. Spanning Tree Protocol Defaults
For detailed information on the operation of the Spanning Tree Protocol,
consult Section 4 of IEEE Standard 802.1D, ISO/IEC 10038:1993.
You can cause serious network performance degradation
if you do not fully understand Spanning Tree concepts. Be
sure to consult personnel experienced with this process
prior to configuring Spanning Tree parameters.
Parameter Description Default Value
Bridge Group
Address Unique MAC group address, recognized by all bridg-
es in the network.
Bridge Identi-
fier Identifier for each bridge. This parameter consists of
two parts: a 16-bit bridge priority and a 48-bit network
adapter address. Ports are numbered in absolute
numbers starting from 1 regardless of their bridge at-
tachment. The network adapter address is the same
address as the first port of the bridge. 32768 (bridge
priority)
Port Identifier Port Identifier Identifies each port of each bridge, with
an incremental default value given for each port.
Port 1 -32768 Port 9 -32776 Port 17 -32784
Port 2 -32769 Port 10 -32777 Port 18 -32785
Port 3 -32770 Port 11 -32778 Port 19 -32786
Port 4 -32771 Port 12 -32779 Port 20 -32787
Port 5 -32772 Port 13 -32780 Port 21 -32788
Port 6 -32773 Port 14 -32781 Port 22 -32789
Port 7 -32774 Port 15 -32782 Port 23 -32790
Port 8 -32775 Port 16 -32783 Port 24 -32791
Port Priority Indicates the priority of a specific port in relation to
other ports. 128
Cost Compo-
nent of Each
Port The Spanning Tree Protocol calculates and ensures
that an active topology generates minimal cost paths.
A value of 100 is generally used for 10Mbps Ethernet
networks, a value of 19 for 100Mbps Fast Ethernet,
and a value of 4 for 1000Mbps Gigabit Ethernet. 19