CHAPTER
13-1
Catalyst 2950 Desktop Switch Software Configuration Guide
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13

Configuring Optional Spannin g-Tree Features

This cha pter descri b es how to configure opt iona l span ning- t ree fea tu res. You can co nfigur e all of t hes e
featu res when your switch is runni ng the per-VL AN spanning-tree (P VS T). You can only configure th e
noted fea ture s w hen you r sw itch i s ru nning the M ult ipl e Spann ing Tree Protoc ol (M STP). To use th ese
features with MSTP, you must have the enhanced software image (EI) installed on your switch.
For informati on on configur ing the Spannin g Tree Protocol (STP), see Cha pter 11, Configuring STP.
For information on configuring the Rapid Spanning Tree Protocol (RSTP) and the Multiple Spanning
Tree Protocol (MSTP), see Chapter 12, Configuring RST P and M STP.
Note For comple te syntax and us age inform ation for the co mmands used in this chapter, refer to th e command
refere nce fo r thi s r ele ase.
This chapter consists of these sections:
Understa nding Opti onal Spanni ng-Tree Features, page 13-1
Configuring O ption al Sp an ning- Tree Featur es, p age 13- 13
Display ing the Spanni ng-Tree Status, pa ge 13-21

Understandin g Optional Sp anning-Tre e Features

These sec tions descr ibe how the optiona l spannin g-tree fe atures work :
Understa ndin g Po rt Fast , pa ge 13 -2
Understa ndin g B PDU Gu ar d, pa ge 13- 3
Understa nding BP DU Filtering , page 13 -3
Understa ndin g U plink Fast, page 1 3-4
Understa ndin g C ross-Stac k Upl inkFast, p age 13-5
Understa ndin g B ackb oneFast, page 13-1 0
Understa nding R oot Guar d, page 13-1 2
Understa ndin g L oo p Gua r d, pa ge 13 -13