© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE I Chapter 6 1 Switching in an Enterprise Network Introducing Routing and Switching in the Enterprise – Chapter 3

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 2 Objectives  Compare the types of switches used in an enterprise network.  Explain how Spanning Tree Protocol prevents switching loops.  Describe and configure VLANs on a Cisco switch.  Describe and configure trunking and Inter-VLAN routing.  Maintain VLANs in an enterprise network.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 3 Compare the Types of Switches Used in an Enterprise Network  Switching and network segmentation  Content addressable memory (CAM)  Virtual circuits

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 4 Compare the Types of Switches Used in an Enterprise Network  Hardware-based Layer 2 switching  Software-based Layer-3 (multilayer) switching

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 5 Compare the Types of Switches Used in an Enterprise Network  Store and forward switching  Cut-through switching Fast-forward Fragment-free

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 6 Compare the Types of Switches Used in an Enterprise Network  Switch physical security  Switch access security

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 7 Explain How Spanning Tree Protocol Prevents Switching Loops  Redundancy in network equipment  Redundant network links  Dangers of switching loops  Broadcast storms

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 8 Explain How Spanning Tree Protocol Prevents Switching Loops  Create a loop-free logical topology  Potential loop detection and port blocking  Redundancy without switching loops

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 9 Explain How Spanning Tree Protocol Prevents Switching Loops  Determining a root bridge  Bridge ID (BID)  Root ports, designated ports, and blocked ports

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 10 Explain How Spanning Tree Protocol Prevents Switching Loops  STP recalculations  Minimizing downtime PortFast UplinkFast BackboneFast

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 11 Explain How Spanning Tree Protocol Prevents Switching Loops  Spanning-tree verification commands

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 12 Explain How Spanning Tree Protocol Prevents Switching Loops  Rapid Spanning Tree Protocol  Discarding  Active topology

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 13 Describe and Configure VLANs on a Cisco Switch  Virtual LANs  Logical networks  Broadcast control  Transparent to end-users

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 14 Describe and Configure VLANs on a Cisco Switch  VLAN functions  VLAN membership Static Dynamic

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 15 Describe and Configure VLANs on a Cisco Switch  VLAN 1: management VLAN  VLAN numbers and names  Port assignment

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 16 Describe and Configure VLANs on a Cisco Switch  VLAN verification commands  Deleting a VLAN  Removing a port from a VLAN

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 17 Describe and Configure VLANs on a Cisco Switch  VLAN ID  Frame tagging: IEEE 802.1Q

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 18 Describe and Configure Trunking and Inter- VLAN Routing  Trunk port characteristics Point-to-point link Carry multiple-VLAN traffic over single link  Support for frame tagging  Trunk modes

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 19  Extending VLANs across switches  Configuring a native VLAN Describe and Configure Trunking and Inter- VLAN Routing

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 20  Connectivity between different VLANs  Subinterfaces  Router-on-a-stick Describe and Configure Trunking and Inter- VLAN Routing

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 21  VLAN Trunking Protocol (VTP) purpose and goals  Management domain  VTP modes: server, client, transparent  VLAN database  Configuration revision number Maintain VLAN Structure on an Enterprise Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 22 Maintain VLAN Structure on an Enterprise Network  VTP messages Summary advertisements Subset advertisements Advertisement requests

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 23  Configuring VTP  Verifying VTP configuration Maintain VLAN Structure on an Enterprise Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 24  VLANs and IP phones  VLANs and wireless security Maintain VLAN Structure on an Enterprise Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 25  VLAN best practices  VLAN security Maintain VLAN Structure on an Enterprise Network

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 26 Summary  Switches forward traffic using store and forward or cut-through techniques  Basic security features should be applied to switches  A VLAN is a way to group hosts on the same logical network even though they may be physically separated  Frame tagging allows a switch to identify the source VLAN of an Ethernet frame.  A Layer 3 device is needed to move traffic between different VLANs.  Subinterfaces allow router interfaces to support multiple VLANs.  VLAN Trunking Protocol provides centralized control, distribution and maintenance of VLANs.

© 2006 Cisco Systems, Inc. All rights reserved.Cisco PublicITE 1 Chapter 6 27