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Characterizing the Existing Network

Designing and Supporting Computer Networks – Chapter 3

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Objectives Diagram and document an existing network to identify

strengths and weaknesses in the design.

Use CCO to determine the appropriate IOS version to support network requirements and download and install the appropriate IOS

Use CCO to determine the appropriate hardware features and install the upgrades using safe practices and procedures

Perform a wireless site survey

Organize collected data into a new network design

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Diagram a Physical Network and Document the Existing Network

Network documentation:

Logical and physical diagrams

Floor plans

Inventory lists for equipment and applications

Current network configuration files

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Diagram a Physical Network and Document the Existing Network

Log in to network devices

Use Cisco IOS software commands to gain information on routers and switches

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Diagram a Physical Network and Document the Existing Network

Create a logical network diagram showing existing addressing, routing, and network segmentation

Illustrate how information flows through the network

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Diagram a Physical Network and Document the Existing Network

Create a modular block diagram

Simplify the network to show major functions

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Diagram a Physical Network and Document the Existing Network

Identify and document the strengths and weaknesses of the existing network

Focus on finding ways to overcome weaknesses

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Use CCO to Determine the Appropriate IOS Version to Support Network Requirements

Cisco CCO features and navigation:

Documentation

Tools

Downloads

Communities and training

News

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Use CCO to Determine the Appropriate IOS Version to Support Network Requirements

Use the show version command

Verify that the inventory list is correct

Obtain missing information

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Use CCO to Determine the Appropriate IOS Version to Support Network Requirements

Select the correct IOS image using the CCO IOS Feature Navigator

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Use CCO to Determine the Appropriate IOS Version to Support Network Requirements

Download the correct IOS

Store new IOS image on TFTP server

Transfer the file to the Cisco router or switch

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Use CCO to Determine the Appropriate IOS Version to Support Network Requirements

Three stages of the router bootup process:

Perform the POST and load the bootstrap program

Locate and load the IOS software

Locate and execute the startup configuration, or enter setup mode

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Use CCO to Determine the Appropriate Hardware Features and Install the Upgrades

Use datasheets to see what modules and interfaces are available

Determine the technologies and media a given device will support

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Use CCO to Determine the Appropriate Hardware Features and Install the Upgrades

Installing a new hardware option on a Cisco router or switch:

Turn off power

Remove blank faceplace

Install option module

Turn on power and check the new configuration

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Perform a Wireless Site Survey

Preparation

Site survey

Security

Safety guidelines

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Perform a Wireless Site Survey

Identify possible sources of signal interference

Identify physical infrastructure issues

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Perform a Wireless Site Survey

Define customer requirements

Identify coverage areas

Determine preliminary access point locations

Measure signal strength

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Organize Collected Data into a New Network Design

Design requirements document:

Overall project goal

Project scope

Network requirements

Current state of the network

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Organize Collected Data into a New Network Design

Identify and record the overall goal of the proposed network design

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Organize Collected Data into a New Network Design

Identify and record the scope of the proposed network upgrade

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Organize Collected Data into a New Network Design

Identify and record the business goals and technical requirements of the proposed network design

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Organize Collected Data into a New Network Design

Characterize the existing network in relation to the identified business goals and technical requirements

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Summary Ensure that network documentation is accurate and

complete before designing an upgrade

Gather information using tools like Cisco Network Assistant

Organize the current network into a modular block diagram to identify where the network needs to be improved.

The Cisco CCO site provides valuable tools and documentation for the design process.

Before producing a wireless network design, it is usually necessary to do a wireless site survey.

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