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Switching in an Enterprise Network

Introducing Routing and Switching in the Enterprise – Chapter 3

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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.

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Compare the Types of Switches Used in an Enterprise Network

Switching and network segmentation

Content addressable memory (CAM)

Virtual circuits

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Compare the Types of Switches Used in an Enterprise Network

Hardware-based Layer 2 switching

Software-based Layer-3 (multilayer) switching

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Compare the Types of Switches Used in an Enterprise Network

Store and forward switching

Cut-through switching

Fast-forwardFragment-free

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Compare the Types of Switches Used in an Enterprise Network

Switch physical security

Switch access security

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Explain How Spanning Tree Protocol Prevents Switching Loops

Redundancy in network equipment

Redundant network links

Dangers of switching loops

Broadcast storms

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Explain How Spanning Tree Protocol Prevents Switching Loops

Create a loop-free logical topology

Potential loop detection and port blocking

Redundancy without switching loops

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Explain How Spanning Tree Protocol Prevents Switching Loops

Determining a root bridge

Bridge ID (BID)

Root ports, designated ports, and blocked ports

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Explain How Spanning Tree Protocol Prevents Switching Loops

STP recalculations

Minimizing downtime

PortFastUplinkFastBackboneFast

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Explain How Spanning Tree Protocol Prevents Switching Loops

Spanning-tree verification commands

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Explain How Spanning Tree Protocol Prevents Switching Loops

Rapid Spanning Tree Protocol

Discarding

Active topology

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Describe and Configure VLANs on a Cisco Switch

Virtual LANs

Logical networks

Broadcast control

Transparent to end-users

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Describe and Configure VLANs on a Cisco Switch

VLAN functions

VLAN membership

StaticDynamic

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Describe and Configure VLANs on a Cisco Switch

VLAN 1: management VLAN

VLAN numbers and names

Port assignment

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Describe and Configure VLANs on a Cisco Switch

VLAN verification commands

Deleting a VLAN

Removing a port from a VLAN

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Describe and Configure VLANs on a Cisco Switch

VLAN ID

Frame tagging: IEEE 802.1Q

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Describe and Configure Trunking and Inter- VLAN Routing

Trunk port characteristicsPoint-to-point linkCarry multiple-VLAN traffic over single link

Support for frame tagging

Trunk modes

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Extending VLANs across switches

Configuring a native VLAN

Describe and Configure Trunking and Inter- VLAN Routing

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Connectivity between different VLANs

Subinterfaces

Router-on-a-stick

Describe and Configure Trunking and Inter- VLAN Routing

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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

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Maintain VLAN Structure on an Enterprise Network

VTP messages

Summary advertisementsSubset advertisementsAdvertisement requests

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Configuring VTP

Verifying VTP configuration

Maintain VLAN Structure on an Enterprise Network

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VLANs and IP phones

VLANs and wireless security

Maintain VLAN Structure on an Enterprise Network

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VLAN best practices

VLAN security

Maintain VLAN Structure on an Enterprise Network

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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.

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