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CCNA 3 v3.0 Module 5 Switches

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Objectives

• LAN design

• LAN switches

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LAN Design Goals

• Functionality

• Scalability

• Adaptability

• Manageability

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LAN Design Considerations

• The function and placement of servers

• Collision-detection issues

• Segmentation issues

• Broadcast domain issues

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LAN Design Methodology

• Gather requirements and expectations

• Analyze requirements and data

• Design the Layer 1, 2, and 3 LAN structure, or topology 

• Document the logical and physical network implementation

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Layer 1 Design

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Typical MDF in Star Topology

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Extended Star Topology in a Multi-Building Campus

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Layer 1 Documentation Logical Diagram

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Cut Sheet

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Layer 2 Design: Developing a LAN Topology

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Microsegmentation of the Network

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Asymmetric Switching

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Layer 2 Switch Collision Domains

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Layer 3 Design

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Use Routers to Impose Logical Structure

Routers provide scalability because they serve as firewalls for broadcasts. They can also provide scalability by dividing networks into subnetworks, or subnets, based on Layer 3 addresses.

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Physical Network Maps

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Setting Up VLAN Implementation

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VLAN Communication

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Access Layer

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Access Layer

• Functions of the Access Layer:

Shared Bandwidth

Switched Bandwidth

MAC Layer Bandwidth

Microsegmentation

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Access Layer Switches

• Catalyst 1900 series

• Catalyst 2820 series

• Catalyst 2950 series

• Catalyst 4000 series

• Catalyst 5000 series

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Distribution Layer

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Distribution Layer

• In a switched network, the distribution layer includes several functions such as the following:

Aggregation of the wiring-closet connections

Broadcast/multicast domain definition

VLAN routing

Any media transitions that need to occur

• Copper to fiber

Security

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Distribution Layer Switches

Cisco Catalyst 2926G

Cisco Catalyst 6000 Family<not pictured>

Cisco Catalyst 5000 Family

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Core Layer

The core layer is a high-speed switching backbone. The core layer should be designed to switch packets as fast as possible.

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Core Layer Switches

<not pictured>

Catalyst 6500 series

IGX 8400 series

Catalyst 8500 series

Lightstream 1010