CCNA Explorer 3 Basic Wireless Concepts and Configuration

Basic Wireless Concepts and Configuration

The Wireless LAN

Why Use Wireless?

Wireless Techonologies

Wireless LANs

WLAN vs. LAN

WLAN Devices

Clients

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 SSID Channels Ad Hoc Networks Basic Service Set Extended Service Set Wireless Beacon Wireless Probe Wireless Authentication Wireless Association Planning the Wireless LAN Map Coverage Area Align Coverage Areas Plan Wireless LAN Security Threats to Wireless Security Unauthorized Access MITM Denial of Service 1 Denial of Service 2 Wireless Security Protocols Wireless Security Protocols Wireless Association EAP TKIP and AES TKIP and AES Securing a Wireless LAN Controlling Access to the Wireless LAN Configuring Wireless LAN Access Configuring the Wireless Access Point Configuration Steps Setup Management Wireless 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 Reason Solution 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