CLI Reference Guide

196 CHAPTER 5: CONFIGURING WX SYSTEM AND ADMINISTRATIVE PARAMETERS
 MSS uses 802.1D bridge protocol data units (BPDUs) on VLAN ports
that are untagged. However, each VLAN still runs its own instance of
STP, even if two or more VLANs contain untagged ports. To run a
single instance of STP in 802.1D mode on the entire switch, configure
all network ports as untagged members of the same VLAN.
 MSS uses PVST+ BPDUs on VLAN ports that are tagged. PVST+ BPDUs
include tag information in the 802.1Q field of the BPDUs. MSS runs a
separate instance of PVST+ on each tagged VLAN.
When you create a VLAN, STP is disabled on the new VLAN by default,
regardless of the STP state of other VLANs on the WX switch.
The IEEE 802.1D spanning tree specifications refer to networking devices
that forward Layer 2 traffic as bridges. In this context, a WX switch is a
bridge. Where this manual or the product interface uses the term bridge,
you can assume the term is applicable to the WX switch.
To configure STP:
1 In the Create VLAN wizard, click Spanning Tree Setup. The Spanning
Tree Setup page appears.
This page does not contain options for enabling fast convergence
features.
2 To enable STP, click Enabled.
3 In the Bridge Priority box, specify this STP bridge’s priority (0 to 65,535).
The default is 32,768 for the WX4400 and 49,152 for the WX1200 and
WXR100.
The bridge with the lowest priority value becomes the root bridge for the
spanning tree.
4 In the Max Age box, specify the maximum age value (6 to 40 seconds),
which controls how long information from other bridges is kept. The
default is 20 seconds.
5 In the Hello Time box, specify the interval (1 to 10 seconds) between each
configuration message from the root bridge. The default is 2 seconds.
6 In the Forward Delay box, specify the amount of time (4 to 30 seconds) a
bridge waits after a topology change to begin forwarding data packets.
The default is 15 seconds.