Cabletron Systems SPECTRUM, User Manual

Page: 126 / 150

Using the 7C0x SmartSwitch Bridge View
6-24 The Spanning Tree Protocol Window
Root Forward Delay
The Forward Delay (in seconds) that will be implemented by this bridge if it is the
Root or becomes the Root. (The Root Bridge in the network sets the Forward
Delay for all bridges in the Spanning Tree network.)
The IEEE 802.1d specification recommends that Forward Delay = 15 seconds, with
an allowable range of 4 to 30 seconds.
Root Max Age
The Max Age value (in seconds) that will be implemented if this bridge is the Root
or becomes the Root. (The Root Bridge in the network sets the Max Age for all
bridges in the Spanning Tree network.)
The IEEE 802.1d specification recommends that Max Age = 20 seconds, with an
allowable range of 6 to 40 seconds.
Root Hello Time
The Hello Time that will be implemented if this bridge is the Root or becomes the
Root.
The IEEE 802.1d specification recommends that Hello Time = 2 seconds, with an
allowable range of 1 to 10 seconds.
The Spanning Tree Port Table button opens the window in which you set
Spanning Tree parameters for individual bridge ports; see
The Spanning Tree
Port Parameters Window , page 6-25 , for more information.
Changing Spanning Tree Parameters
To change the Bridge Priority, Root Forward Delay, Root Max Age, or Root Hello
Time:
1. In the Spanning Tree Protocol window, highlight the current value of the field
you want to change.
2. Type the new value in the appropriate text box and press Enter or Return on
the keyboard.
TIP
To ensure proper operation of the Spanning Tree Algorithm, the IEEE 802.1d specification
recommends that you always observe the following relationship between Forward Delay
and Max Age:
2 x (Forward Delay - 1.0) > Max Age