ZyXEL Communications XS3800-28, User Manual, Page: 381 / 789

Chapter 54 Spanning Tree Protocol
XS3800-28 User’s Guide
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Figure 283 SWITCHING > Spanning Tree Protocol > Spanning Tree Setup
The following table describes the labels in this screen.
Table 185 SWITCHING > Spanning Tree Protocol > Spanning Tree Setup
LABEL DESCRIPTION
Spanning Tree
Mode You can activate one of the STP modes on the Switch.
Select Rapid Spanning Tree (RSTP) , Multiple Rapid Spanning Tree (MRSTP) or Multiple Spanning
Tree (MSTP) .
Auto Path-cost Mode
Auto Path-cost Mode allows you to have the Switch automatically set the path cost for each port according to
their link speed. The Switch uses the path costs to determine the best path to the root bridge in a spanning tree.
There are three
Auto Path-cost Mode s that supports different path cost lengths:
• Short (16-bit)
• Long (32-bit)
• User-defined (32-bit).
The auto path cost values of each mode are described in Section 54.3 on page 379 .
Note: It is recommended to use the same Auto Path-cost Mode on all switches within the spanning
tree network system.
To use the auto path-cost feature, select the Auto Path-cost mode ( Short , Long , User-defined ), set a port’s Path Cost
(in the SWITCHING > Spanning Tree Protocol > RSTP , MRSTP , and MSTP screens) to “0”. The Switch will automatically
set the port’s path cost to the auto path cost value defined by the Auto Path-cost Mode you select.
Short Select this mode if you want to use the 16-bit auto path cost values the Switch defines.
Long Select this mode if you want to use the 32-bit auto path cost values the Switch defines.
User-defined Select this mode to manually set the auto path costs for each link speed. Enter the path cost
value for each link speed. The range is from 1 – 2000000. It is recommended to assign this value
according to link speeds. The slower the speed, the higher the cost.