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Allied Telesis AT-S39 User Manual

Page 110

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Chapter 12: Rapid Spanning Tree Protocol Commands

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hellotime

Specifies the time interval between generating and

sending configuration messages by the bridge. This
parameter can be from 1 to 10 seconds. The default is
2 seconds.

forwarddelay

Specifies the waiting period before a bridge changes

to a new state, for example, becomes the new root
bridge after the topology changes. If the bridge
transitions too soon, not all links may have yet
adapted to the change, resulting in network loops.
The default is 15 seconds. This parameter effects only
those ports operating in the STP compatible mode.

maxage

Specifies the length of time after which stored bridge

protocol data units (BPDUs) are deleted by the bridge.
All bridges in a bridged LAN use this aging time to test
the age of stored configuration messages called
bridge protocol data units (BPDUs). For example, if you
use the default 20, all bridges delete current
configuration messages after 20 seconds. This
parameter can be from 6 to 40 seconds. The default is
20 seconds.

Note

The value for the maxage parameter must be less than
(2 x (hellotime +1)) and less than (2 x (forwarddelay -1)).

forceversion

The forceversion parameter lets you choose
between

forcestpcompatible

The bridge will use the RSTP
parameter settings, but will
transmit only STP BPDU
packets out the ports.

normalrspt

The bridge will use RSTP. This
is the default setting.

7

28672

15

61440

Table 1 RSTP Bridge Priority Value Increments

Increment

Bridge
Priority

Increment

Bridge
Priority