Allied-telesis AT-S101 Uživatelský manuál stáhnout pdf (Strana 135)

AT-S101 Management Software User’s Guide

135

Bridge Priority and the Root Bridge

The first task that bridges perform when a spanning tree protocol is

activated on a network is the selection of a root bridge. A root bridge

distributes network topology information to the other network bridges and

is used by the other bridges to determine if there are redundant paths in

the network.

A root bridge is selected by the bridge priority number, also referred to as

the bridge identifier, and sometimes the bridge’s MAC address. The bridge

with the lowest bridge priority number in the network is selected as the root

bridge. If two or more bridges have the same bridge priority number, of

those bridges the one with the lowest MAC address is designated as the

root bridge.

You can change the bridge priority number in the AT-S101 Management

Software. You can designate which switch on your network as the root

bridge by giving it the lowest bridge priority number. You may also

consider which bridge should function as the backup root bridge in the

event you need to take the primary root bridge offline and assign that

bridge the second lowest bridge identifier number.

The bridge priority has a range 0 to 61440 in increments of 4096. To make

this easier for you, the AT-S101 Management Software divides the range

into increments. You specify the increment that represents the desired

bridge priority value. The range is divided into sixteen increments, as

shown in Table 2.

Table 2. Bridge Priority Value Increments

Increment

Bridge

Priority

Increment

Bridge

Priority

0 0 8 32768

1 4096 9 36864

2 8192 10 40960

3 12288 11 45056

4 16384 12 49152

5 20480 13 53248

6 24576 14 57344

7 28672 15 61440

1 2 ... 130 131 132 133 134 135 136 137 138 139 140 ... 237 238

Žádné komentáře

Allied-telesis AT-S101 Uživatelský manuál Strana 135