Specifications

RoamAbout Mobility System Software Configuration Guide 13-1
13
Configuring and Managing
Spanning Tree Protocol
Spanning Overview
ThepurposeoftheSpanningTreeProtocol(STP)istomaintainaloop‐freenetwork.Aloop‐free
pathisaccomplishedwhenadevicerecognizesaloopinthetopologyandblocksoneormore
redundantpaths.
MobilitySystemSoftware(MSS)supports802.1DandPer‐VLANSpanningTreeprotocol(PVST+).
•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doesnotsupportrunning
802.1DonmultipletaggedVLANs.
•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.
For information about... Refer to page...
Spanning Overview 13-1
Enabling the Spanning Tree Protocol 13-2
Changing Standard Spanning Tree Parameters 13-2
Configuring and Managing STP Fast Convergence Features 13-7
Displaying Spanning Tree Information 13-11
Spanning Tree Configuration Scenario 13-15
Notes:
• STP does not run on wired authentication ports and does not affect traffic flow on these port
types.
• When you create a VLAN, STP is disabled on the new VLAN by default, regardless of the STP
state of other VLANs on the device.
• The IEEE 802.1D spanning tree specifications refer to networking devices that forward Layer 2
traffic as bridges. In this context, a RoamAbout Switch is a bridge. Where this manual or the
product interface uses the term bridge, you can assume the term is applicable to the RoamAbout
Switch.