Specifications

Spanning Tree Configuration Summary
6-2 Spanning Tree Configuration
onlyiftheforwardinglinkgoesdown.MSTPassignseachVLANpresentonthenetworktoa
particularSpanningTreeinstance,allowingeachswitchporttobeinadistinctstateforeachsuch
instance:blockingforoneSpanningTreewhileforwardingforanother.Thus,trafficassociated
withonesetof
VLANscantraverseaparticularinter‐switchlink,whiletrafficassociatedwith
anothersetofVLANscanbeblockedonthatlink.IfVLANsareassignedtoSpanningTrees
wisely,nointer‐switchlinkwillbecompletelyidle,maximizingnetworkutilization.
FordetailsoncreatingSpanningTreeinstances,referto
“setspantreemsti”onpage 6‐12.
FordetailsonmappingSpanningTreeinstancestoVLANs,referto“setspantreemstmap”on
page 6‐13.
Spanning Tree Features
TheSecureStackC3devicemeetstherequirementsoftheSpanningTreeProtocolsbyperforming
thefollowingfunctions:
• CreatingasingleSpanningTreefromanyarrangementofswitchingorbridgingelements.
• Compensatingautomaticallyforthefailure,removal,oradditionofanydeviceinanactive
datapath.
•Achievingportchangesinshorttime
intervals,whichestablishesastableactivetopology
quicklywithminimalnetworkdisturbance.
•Usingaminimumamountofcommunicationsbandwidthtoaccomplishtheoperation ofthe
SpanningTreeProtocol.
• Reconfiguringtheactivetopologyinamannerthatistransparenttostationstransmittingand
receivingdatapackets.
• Managingthetopologyinaconsistentand
reproduciblemannerthroughtheuseofSpanning
TreeProtocolparameters.
Note: MSTP and RSTP are fully compatible and interoperable with each other and with legacy
STP 802.1D.
Note: The term “bridge” is used as an equivalent to the term “switch” or “device” in this document.