Enhancements in Release F.04.08

Configuring Rapid Reconfiguration Spanning Tree (RSTP)

Reconfiguring Whole-Switch Spanning Tree Values. You can configure one or more of the

following parameters, which affect the Spanning Tree operation of the whole switch:

Table 9. Whole-Switch RSTP Parameters

Parameter

Default

Description

 

 

 

protocol-version

RSTP

Identifies which of the Spanning Tree protocols will be used when Spanning

 

 

Tree is enabled on the switch.

 

 

 

force-version

rstp-operation

Sets the Spanning Tree compatibility mode. Even if rstp-operationis selected

 

 

though, if the switch detects STP BPDU packets on a port, it will communicate

 

 

to the attached device using STP BPDU packets.

 

 

If errors are encountered, as described in the Note on page 138, the Force-

 

 

Version value can be set to stp-compatible, which forces the switch to commu-

 

 

nicate out all ports using operations that are compatible with IEEE 802.1D STP.

 

 

 

priority

32768

Specifies the protocol value used along with the switch MAC address to

 

(8 as a step value)

determine which device in the Spanning Tree is the root. The lower the priority

 

 

value, the higher the priority.

 

 

The value you enter has changed from the STP value. The range is 0 - 61440, but

 

 

for RSTP the value is entered as a multiple (a step) of 4096. You enter a value in

 

 

the range 0 - 15. The default value of 32768 is derived by the default setting of 8.

 

 

Displaying the RSTP configuration (show spanning-tree config) shows 8, but

 

 

displaying the RSTP operation (show spanning-tree) shows 32768.

 

 

 

*maximum-age

20 seconds

Sets the maximum age of received Spanning Tree information before it is

 

 

discarded. The range is 6 to 40 seconds.

 

 

 

*hello-time

2 seconds

Sets the time between transmission of Spanning Tree messages. Used only

 

 

when this switch is the root. The range is 1 to 10 seconds.

 

 

 

*forward-delay

15 seconds

Sets the time the switch waits between transitioning ports from listening to

 

 

learning and from learning to forwarding states. The range is 4 to 30 seconds.

*These parameters are the same for RSTP as they are for STP. The switch uses its own maximum-age, hello-time, and forward-delay settings only if it is operating as the root device in the Spanning Tree. If another device is the root device, then the switch uses the other device’s settings for these parameters.

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