ZyXEL XGS4700-48F User Guide - Page 149

CHAPTER 13 Spanning Tree Protocol The Switch supports Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP) and Multiple Spanning Tree Protocol (MSTP) as defined in the following standards. • IEEE 802.1D Spanning Tree Protocol • IEEE 802.1w Rapid Spanning Tree Protocol • IEEE 802.1s Multiple Spanning Tree Protocol The Switch also allows you to set up multiple STP configurations (or trees). Ports can then be assigned to the trees. 13.1 STP/RSTP Overview (R)STP detects and breaks network loops and provides backup links between switches, bridges or routers. It allows a Switch to interact with other (R)STPcompliant switches in your network to ensure that only one path exists between any two stations on the network. The Switch uses IEEE 802.1w RSTP (Rapid Spanning Tree Protocol) that allows faster convergence of the spanning tree than STP (while also being backwards compatible with STP-only aware bridges). In RSTP, topology change information is directly propagated throughout the network from the device that generates the topology change. In STP, a longer delay is required as the device that causes a topology change first notifies the root bridge and then the root bridge notifies the network. Both RSTP and STP flush unwanted learned addresses from the filtering database. In RSTP, the port states are Discarding, Learning, and Forwarding. Note: In this user's guide, "STP" refers to both STP and RSTP. 13.1.1 STP Terminology The root bridge is the base of the spanning tree. XGS4700-48F User's Guide 149