1 © 2003, Cisco Systems, Inc. All rights reserved. CCNA 3 v3.0 Module 7 Spanning Tree Protocol

222 © 2003, Cisco Systems, Inc. All rights reserved. Purpose of This PowerPoint This PowerPoint primarily consists of the Target Indicators (TIs) of this module in CCNA version 3.0. It was created to give instructors a PowerPoint to take and modify as their own. This PowerPoint is: NOT a study guide for the module final assessment. NOT a study guide for the CCNA certification exam. Please report any mistakes you find in this PowerPoint by using the Academy Connection Help link.

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444 © 2003, Cisco Systems, Inc. All rights reserved. Objectives Redundant topologies Spanning Tree Protocol

555 © 2003, Cisco Systems, Inc. All rights reserved. Redundant topologies

666 © 2003, Cisco Systems, Inc. All rights reserved. Redundancy Redundant networking topologies are designed to ensure that networks continue to function in the presence of single points of failure.

777 © 2003, Cisco Systems, Inc. All rights reserved. Redundant Topologies A goal of redundant topologies is to eliminate network outages caused by a single point of failure. All networks need redundancy for enhanced reliability.

888 © 2003, Cisco Systems, Inc. All rights reserved. Simple Redundant Switched Topology

999 © 2003, Cisco Systems, Inc. All rights reserved. Broadcast Storm

10 © 2003, Cisco Systems, Inc. All rights reserved. Multiple Frame Transmissions

11 © 2003, Cisco Systems, Inc. All rights reserved. Media Access Control Database Instability In a redundant switched network, it is possible for switches to learn the wrong information. A switch can learn that a MAC address is on a port when it is not.

12 © 2003, Cisco Systems, Inc. All rights reserved. Spanning Tree Protocol

13 © 2003, Cisco Systems, Inc. All rights reserved. Using Bridging Loops for Redundancy

14 © 2003, Cisco Systems, Inc. All rights reserved. Spanning-Tree Protocol

15 © 2003, Cisco Systems, Inc. All rights reserved. Spanning Tree Link Costs

16 © 2003, Cisco Systems, Inc. All rights reserved. A Spanning Tree

17 © 2003, Cisco Systems, Inc. All rights reserved. Spanning-Tree Operation One root bridge per network. One root port per nonroot bridge. One designated port per segment. Nondesignated ports are unused.

18 © 2003, Cisco Systems, Inc. All rights reserved. Bridge Protocol Data Unit Bridge protocol data unit (BPDU)

19 © 2003, Cisco Systems, Inc. All rights reserved. Bridge IDs

20 © 2003, Cisco Systems, Inc. All rights reserved. Spanning-Tree Port States

21 © 2003, Cisco Systems, Inc. All rights reserved. Spanning-Tree Recalculation A switched internetwork has converged when all the switch and bridge ports are in either the forwarding or blocked state.

22 © 2003, Cisco Systems, Inc. All rights reserved. Rapid Spanning-Tree Protocol The standard and protocol introduce the following: Clarification of port states and roles Definition of a set of link types that can go to forwarding state rapidly Allowing switches, in a converged network, to generate their own BPDUs rather than relaying root bridge BPDUs

23 © 2003, Cisco Systems, Inc. All rights reserved. Rapid Spanning-Tree Port Designations The Rapid Spanning Tree Protocol, IEEE 802.1w, will eventually replace the Spanning Tree Protocol, IEEE 802.1D.