Spanning Tree Setup - ZyXEL Communications XMG1930-30 User Manual

53.3 Spanning Tree Setup

There are three Auto path-cost Modes (see
according to the device average link speeds in the STP network.
If most of your devices support high link speed, you should select Long or User-defined mode. The path
cost of link speed slower than 10 Mbps can be set to 2000000, and the path cost of link speed faster than
10 Gbps can be set to 200. This way, the path costs can better reflect actual link speeds with a wider
range (32 bits) of path cost values. If the link speeds within the system are averagely smaller than 1
Gbps, you should select Short mode since Short mode have path cost values more detailed defined for
link speeds under1 Gbps.
The path cost values are described in the following tables.
The Switch defines the following Short mode path costs.
Table 182 Auto Path Cost Mode: Short
LINK SPEED
Up to 4 Mbps
Up to 10 Mbps
Up to 16 Mbps
Up to 100 Mbps
Up to 1 Gbps
Up to 10 Gbps
More than 10 Gbps
The Switch defines the following Long mode path costs.
Table 183 Auto Path Cost Mode: Long
LINK SPEED
Up to 10 Mbps
Up to 100 Mbps
Up to 1 Gbps
Up to 2.5 Gbps
Up to 5 Gbps
Up to 10 Gbps
More than 10 Gbps
If you do not configure the auto path cost values for User-defined mode, the Switch uses the following
default values.
Table 184 Auto Path Cost Mode: User-defined
LINK SPEED
Up to 10 Mbps
Up to 100 Mbps
Up to 1 Gbps
Up to 2.5 Gbps
Chapter 53 Spanning Tree Protocol
Table 185 on page
AUTO PATH COST VALUE
250
100
62
19
4
2
1
AUTO PATH COST VALUE
2000000
200000
20000
8000
4000
2000
200
AUTO PATH COST VALUE
2000000
200000
20000
8000
XMG1930 Series User's Guide
352
354). Choose the Auto Path-cost Mode