Chapter 7: Basic Wireless Concepts and Configuration
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Chapter 7: Basic WirelessConcepts and Configuration
CCNA Exploration 4.0
1
CCNA Exploration 4.0
Objectives
• Describe the components and operations of basicwireless LAN topologies.
• Describe the components and operations of basicwireless LAN security.
• Configure and verify basic wireless LAN access.• Configure and troubleshoot wireless client access.
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• Describe the components and operations of basicwireless LAN topologies.
• Describe the components and operations of basicwireless LAN security.
• Configure and verify basic wireless LAN access.• Configure and troubleshoot wireless client access.
The Wireless LAN
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Why Use Wireless?
• Business networks today are evolving to support peoplewho are on the move.
• Mobility environment: where people can take theirconnection to the network along with them on the road.
• There are many different infrastructures (wired LAN,service provider networks) that allow mobility like this tohappen, but in a business environment, the most importantis the WLAN.
• People now expect to be connected at any time and place
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• Business networks today are evolving to support peoplewho are on the move.
• Mobility environment: where people can take theirconnection to the network along with them on the road.
• There are many different infrastructures (wired LAN,service provider networks) that allow mobility like this tohappen, but in a business environment, the most importantis the WLAN.
• People now expect to be connected at any time and place
Wireless Technologies
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PAN(Personal Area
Network)
LAN(Local Area Network)
WAN(Wide Area Network)
MAN(Metropolitan Area Network)
Wireless Will Be Everywhere
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PAN(Personal Area
Network)
Wireless LAN
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Comparing a WLAN to a LAN
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• In an 802.3 Ethernet LAN, each client hasa cable that connects the client NIC to aswitch. The switch is the point where theclient gains access to the network.
• In a wireless LAN, each client uses awireless adapter to gain access to thenetwork through a wireless device such asa wireless router or access point.
What is WLAN RF Technology?
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Modulation
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802.11b Radio Modulation
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802.11b Direct Sequence Modulation
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2.4-GHz Channel Sets
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802.11b Access Point Coverage
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802.11b Scalability
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Comparing the Technologies 802.11a Data Rates
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802.11a Uses OFDM Modulation
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802.11a 5-GHz Frequency Bands
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802.11a Access Point Coverage
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802.11a Scalability (Indoor UNII-1 and UNII-2)
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Wireless standards
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Wireless Infrastructure Components
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Configurable Parameters for Wireless Endpoints
• Wireless mode• Wireless Network Name: SSID• Wireless Channel:
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802.11 Topologies: Ad hoc Network
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802.11 Topologies: Basic Service Sets
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802.11 Topologies: Extended Service Sets
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802.11 Frame Format
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802.11 Frames Type
• There are three types of MAC frames, namely:• Control Frame:
– RTS, CTS, ACK• Data Frame• Management Frame:
– Beacon– Probe Req, Probe Resp– Assoc Req, Assoc Resp– Reassoc Req, Reassoc Resp– Disassociation– Authentication– Deauthentication
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• There are three types of MAC frames, namely:• Control Frame:
– RTS, CTS, ACK• Data Frame• Management Frame:
– Beacon– Probe Req, Probe Resp– Assoc Req, Assoc Resp– Reassoc Req, Reassoc Resp– Disassociation– Authentication– Deauthentication
802.11 Frames Type (cont)
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Client and Access Point Association
• Beacon
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Client and Access Point Association
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Client and Access Point Association
Step 3 - 802.11 Association
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Planning the Wireless LAN
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Planning the Wireless LAN
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Planning the Wireless LAN
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Planning the Wireless LAN
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Wireless LAN Security
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Wireless LAN Security Threats
Unauthorized Access
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Wireless LAN Security Threats
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Wireless LAN Security Threats
Denial of Service
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Wireless Security Protocols
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Authentication and Encryption
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802.11 Open Authentication
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802.11 Shared Key Authentication
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Wireless Security Protocols
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Wireless Security Protocols
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Wireless Security Protocols
• Encryption
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Securing a Wireless LAN
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Configure Wireless LAN Access
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Configuring the Wireless Access Point
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Setup: Basic Setup
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Administration: Management
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Configuring Basic Wireless Settings
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Security Mode
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• Select the mode you want to use: PSK-Personal, PSK2-Personal, PSK-Enterprise, PSK2-Enterprise, RADIUS, orWEP.
Mode Parameters
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• Enterprise modes are not configured in this chapter
Configure Encryption and Key
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Configure a wireless NIC: Scan SSID
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Configure a wireless NIC: Scan SSID
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Select the Wireless Security Protocol
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• Practice: 7.3.2.4
TroubleshootingSimple WLAN Problems
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TroubleshootingSimple WLAN Problems
Systematic Approach to WLAN Troubleshooting
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• Step 1 - Eliminate the client device as the source of theproblem.
• Step 2 - Confirm the physical status of WLAN devices.• Step 3 - Inspect wired links.
Updating the Access Point Firmware
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Incorrect Channel Settings
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Incorrect Channel Settings: Solution
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Solving RF Interference
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Solving RF Interference
• Site Surveys
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Site Survey
• Two categories: Manual and utility assisted.• Manual site surveys can include a site evaluation to be
followed by a more thorough utility-assisted site survey. Asite evaluation involves inspecting the area with the goal ofidentifying potential issues that could impact the network.Specifically, look for the presence of multiple WLANs,unique building structures, such as open floors andatriums, and high client usage variances, such as thosecaused by differences in day or night shift staffing levels.
• Note: you do not conduct site surveys as part of this course
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• Two categories: Manual and utility assisted.• Manual site surveys can include a site evaluation to be
followed by a more thorough utility-assisted site survey. Asite evaluation involves inspecting the area with the goal ofidentifying potential issues that could impact the network.Specifically, look for the presence of multiple WLANs,unique building structures, such as open floors andatriums, and high client usage variances, such as thosecaused by differences in day or night shift staffing levels.
• Note: you do not conduct site surveys as part of this course
Access Point Misplacement
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Access Point Misplacement: Solution
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Access Point Misplacement: Solution
• Ensure that access points are not mounted closer than 7.9 inches (20cm) from the body of all persons.
• Do not mount the access point within 3 feet (91.4 cm) of metalobstructions.
• Install the access point away from microwave ovens. Microwave ovensoperate on the same frequency as the access point and can causesignal interference.
• Always mount the access point vertically (standing up or hangingdown).
• Do not mount the access point outside of buildings.• Do not mount the access point on building perimeter walls, unless
outside coverage is desired.• When mounting an access point in the corner of a right-angle hallway
intersection, mount it at a 45-degree angle to the two hallways. Theaccess point internal antennas are not omnidirectional and cover alarger area when mounted this way.
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• Ensure that access points are not mounted closer than 7.9 inches (20cm) from the body of all persons.
• Do not mount the access point within 3 feet (91.4 cm) of metalobstructions.
• Install the access point away from microwave ovens. Microwave ovensoperate on the same frequency as the access point and can causesignal interference.
• Always mount the access point vertically (standing up or hangingdown).
• Do not mount the access point outside of buildings.• Do not mount the access point on building perimeter walls, unless
outside coverage is desired.• When mounting an access point in the corner of a right-angle hallway
intersection, mount it at a 45-degree angle to the two hallways. Theaccess point internal antennas are not omnidirectional and cover alarger area when mounted this way.
Problems with Authentication and Encrytion
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Problems with Authentication and Encrytion
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Problems with Authentication and Encrytion
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Summary
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