CCNA Explorer 3 Basic Wireless Concepts and Configuration

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Basic Wireless Concepts and Configuration

The Wireless LAN

Why Use Wireless?

Wireless Techonologies
Wireless LANs
WLAN Devices

Wireless LAN Standards

WLAN Graph
WLAN Table
Wi-Fi Certifications
  • ITU-R regulates allocation of RF bands.
  • IEEE specifies how RF is modulated to carry information.
  • Wi-Fi ensures that vendors make devices that are interoperable.

Wireless Infratructure Components

Wireless NICs
Wireless Access Points
Hidden Nodes

CSMA/CA - Carrier Sense Multiple Access with Collision Avoidance
(RTS/CTS) - CSMA/CA feature called request to send/clear to send

Wireless Routers

Wireless Operation

Configure Wireless AP
Wireless modes
Ad Hoc Networks
Basic Service Set
Extended Service Set
Wireless Beacon
Wireless Probe
Wireless Authentication
Wireless Association

Planning the Wireless LAN

Coverage Area
Align Coverage Areas

Wireless LAN Security

Threats to Wireless Security

Unauthorized Access
Denial of Service 1
Denial of Service 2

Wireless Security Protocols

Wireless Security Protocols
Wireless Association

Securing a Wireless LAN

Controlling Access to the Wireless LAN

Configuring Wireless LAN Access

Configuring the Wireless Access Point

Configuration Steps
Configuration overview
Configure mode
Configure SSID
Confiugre Radio Band
Configure Wide Channel
Configure standard channel
Wireless Security - Overview
Wireless Security - Mode
Wireless Security - Mode Parameters
Wireless Security - Encryption
Wireless Security - Key

Configuring Wireless NIC

Scan for SSIDs
Choose SSID
Configure wireless Security
Configure wireless security step 1
Configure wireless security step 2
Configure wireless security step 3
Configure wireless security step 4
Configure wireless security step 5
Configure wireless security step 6
Configure wireless security step 7
Configure wireless security step 8
Verify Wireless connectivity

Troubleshooting Simple WLAN Problems

Solve Access Point Radio and Firmware Issues

Troubleshoot wireless
  • Eliminate the user PC as the source of the problem.
    • Confirm the network configuration on the PC using the ipconfig command. Verify that the PC has received an IP address via DHCP or is configured with a static IP address.
    • Confirm that the device can connect to the wired network. Connect the device to the wired LAN and ping a known IP address.
    • It may be necessary to try a different wireless NIC. If necessary, reload drivers and firmware as appropriate for the client device.
    • If the wireless NIC of the client is working, check the security mode and encryption settings on the client. If the security settings do not match, the client cannot get access to the WLAN.
    • How far is the PC from an access point? Is the PC out of the planned coverage area (BSA).
    • Check the channel settings on the client. The client software should detect the appropriate channel as long as the SSID is correct.
    • Check for the presence of other devices in the area that operate on the 2.4 GHz band.
  • Confirm the physical status of devices.
    • Are all the devices actually in place? Consider a possible physical security issue.
    • Is there power to all devices, and are they powered on?
  • Inspect links.
    • Inspect links between cabled devices looking for bad connectors or damaged or missing cables.
    • If the physical plant is in place, use the wired LAN to see if you can ping devices including the access point.

Solve Access Point Radio and Firmware Issues

Download Firmware
Select Firmware
Run Firmware Upgrade

Incorrect Channel Settings

Channel problem

Solve Access Point Radio and Firmeware Issues

RF problem
RF Reason
RF Solution
Misplacement Problem
Misplacement Reason
Misplacement Solution

Problems with Authentication and Encryption

Authentication Problem
Authentication Reason
Authentication Solution

Chapter Summary

Chapter Summary