Cisco WS-C4003 Software Guide - Page 133

CH A P T E R 8 Configuring Spanning Tree PortFast, UplinkFast, and BackboneFast, and Loop Guard This chapter describes how to configure the PortFast, UplinkFast, and BackboneFast, and loop guard spanning tree enhancements on the Catalyst enterprise LAN switches. Note For information on configuring spanning tree, see Chapter 7, "Configuring Spanning Tree." Note For complete syntax and usage information for the commands used in this chapter, refer to the Command Reference-Catalyst 4000 Family, Catalyst 2948G, and Catalyst 2980G Switches. This chapter consists of these sections: • Understanding How PortFast Works, page 8-1 • Configuring PortFast, page 8-2 • Understanding How PortFast BPDU Guard Works, page 8-3 • Configuring PortFast BPDU Guard, page 8-3 • Understanding How PortFast BPDU Filtering Works, page 8-6 • Configuring PortFast BPDU Filtering, page 8-6 • Understanding How UplinkFast Works, page 8-8 • Configuring UplinkFast, page 8-9 • Understanding How BackboneFast Works, page 8-11 • Configuring BackboneFast, page 8-13 • Understanding How Loop Guard Works, page 8-15 • Configuring Loop Guard, page 8-17 Understanding How PortFast Works Spanning tree PortFast causes a port to enter the spanning tree forwarding state immediately, bypassing the listening and learning states. You can use PortFast on switch ports connected to a single workstation or server to allow those devices to connect to the network immediately, instead of waiting for the port to transition from the listening and learning states to the forwarding state. 78-12647-02 Software Configuration Guide-Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4 8-1