Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 579

33 Spanning Tree Protocol (STP) Overview The spanning tree protocol (STP) is a Layer 2 protocol-specified by IEEE 802.1d-that eliminates loops in a bridged topology by enabling only a single path through the network. By eliminating loops, the protocol improves scalability in a large network and allows you to implement redundant paths, which can be activated after the failure of active paths. Layer 2 loops, which can occur in a network due to poor network design and without enabling protocols like xSTP, can cause unnecessarily high switch CPU utilization and memory consumption. Table 33-1 lists the variations of STP that FTOS supports. Table 33-1. FTOS Supported Spanning Tree Protocols Dell Force10 Term Spanning Tree Protocol (STP) Rapid Spanning Tree Protocol (RSTP) Multiple Spanning Tree Protocol (MSTP) Per-VLAN Spanning Tree Plus (PVST+) IEEE Specification 802.1d 802.1w 802.1s Third Party This chapter contains the following sections: • Configuring Spanning Tree • Configuring Interfaces for Layer 2 Mode • Enabling Spanning Tree Protocol Globally • Adding an Interface to the Spanning Tree Group • Removing an Interface from the Spanning Tree Group • Modifying Global Parameters • Modifying Interface STP Parameters • Enabling PortFast • BPDU Filtering • STP Root Selection • STP Root Guard • SNMP Traps for Root Elections and Topology Changes • Displaying STP Guard Configuration Spanning Tree Protocol (STP) | 577