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Wireless Chapter 7

CCNA Exploration Semester 3

Modified by Profs. Ward

and Cappellino

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Topics

Components and basic operation of wireless LANs

Basic WLAN security Configure and verify basic wireless LAN

access Troubleshoot wireless client access

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Semester 3

LAN Design

Basic Switch Concepts

VLANs

VTP

STP

Inter-VLAN routing

Wireless-

Chp 7

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Wireless Review

Wireless was covered in CSN208, therefore, only new material will be presented here Must have understanding of entire chapter Please see me, the curriculum or the CSN208

text with questions Review- what is an AP? Review- what is a wireless NIC?

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Wireless router Acts as:

Router for use in ___________________ Ethernet ______________ and wireless __________________________

Configuration on both the ____________________ is necessary

Parameters: Mode refers to the 802.11a, b, g, or n Configure SSID – what is the SSID? Select channel within 2.4GHz band

_________________________ should be set to use _____________________________-

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Channel Graph

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Different 802.11 Wireless Topologies…

Ad Hoc Basis Service Set (BSS) Extended Service Set (ESS)

More to come on each of these…

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______________ topology

WLAN operating with _________________

_________________ Negotiate parameters Independent basic

service set Area covered is basic

service area (_____)

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__________________ topology

_________________ Access point _________

_______________________________________ for clients

Uses _________ mode Area covered is basic

service area (_______).

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________________ topology

________________________________________

Access point manages parameters for clients

__________ mode used Area covered is extended

service area (_____).

A common distribution system allows multiple access points in an ESS to appear to be a single BSS.

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Beacon and probe Discovering a WLAN and connecting to it involves the

following components: ________ - _________ used by the WLAN

networks to _____________________ Access point may send out a beacon at regular intervals for

________________________ _________ - Frames _____________________

________________________ Client sends a probe specifying the _____________

supported. ________________________ Client can send probe with no SSID to look for any network.

Access point may be configured to respond, or not.Components continued on next slide…

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Authentication

Components cont… ______________ One of three ___________

__________________________ __________________________ ____________________________ 802.11 had two authentication mechanisms.

________ (Open Authentication) does not give privacy

Wired Equivalency Protection (__________) Newer and more secure authentication method:

Wi-Fi Protected Access (_________)

Components continued on next slide…

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Association Components cont… _______________ - The process for _________

___________________________________________________________________ Request from client and response. Finalizes __________________ Finalizes ____________________ ________________________ ____________ the access point MAC address (_______) Access point maps a logical port known as the association

identifier (AID) to the WLAN client. Traffic can then flow between the two devices

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Planning the WLAN

Implement a _____________________ prior to construction of a WLAN

RF is a shared medium so the ______________ ______________________ for RF Place AP:

Above obstructions/ at least 3 feet from metal obstructions Vertically and high up/in the ceiling. In locations where users will work.

Work out the coverage for each AP. ___________________________

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Wireless Security/Protocol review

These topics are also a review of the same material covered in CSN208

Review- what are some security threats? Review- what are some disruptive attacks

that could affect a business? Review- what are some Wireless protocols

we have studied? Review- what type of encryption does

Wireless use?

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Controlling Access to the Wireless LAN

Possibilities for controlling access: ___________________ - __________________________

from access points __________ considered a ___________________ since

SSID can still be easily discovered ____________________ - Tables are manually

constructed on the access point to _________________ __________________________________ _____________ considered a way to secure a WLAN since

______________________________ WLAN _____________________ - ________________ ______________________________ of the AP

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Configuring Access Point

Remember: To configure and test incrementally Most access points have been _______________________

______________________ with the default settings ________________________________!

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Basic Wireless Settings

_______________ – Lets you choose the right mode for your devices. B, G, N, mixed or BG mixed. You can disable wireless operation.

__________________ – should be changed from the default. ______________________________ on the

network. _____________ can be enabled or disabled.

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More Basic Wireless Settings

Radio Band – For best performance, keep the __________. For Wireless-N devices only, select Wide -

40MHz Channel. If you selected Wide for the Radio Band, Select a

channel from the drop-down menu of the “Wide Channel” parameter

For Wireless-G and Wireless-B only, select Standard - 20MHz Channel. If you selected Standard for the Radio Band, Select a

channel from the drop-down menu of the “Standard Channel” parameter

See summary graphic next slide…

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Summary of Linksys Settings

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Configure Security on the Linksys

Security mode Mode parameters RADIUS Server IP address RADIUS Server Port Encryption Pre-shared Key Key Renewal

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Configure Security on the Linksys cont…

Choose _____________________ if all client devices are able to use it. If some older devices do not support WPA2 then choose

the best security mode that is supported by all devices.

Encryption – _______________________. Use AES with WPA2.

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Configure the client After the access point has been configured, you

need to ___________________________________ to allow it to connect to the wireless network.

First, scan for available WLAN’s and SSID’s If a WLAN does not show up on an auto scan- what

could be the problem? Proceed manually

Add a wireless network Enter the SSID Choose the authentication method Choose the encryption method Enter the network key.

Now confirm connectivity with the AP using ping

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Troubleshooting _____________

Generally start with the ___________________ __________________ the TCP/IP stack…

Check the ________________________ then Update __________________

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Troubleshooting – no connectivity

Check that the PC has an ___________ Try connecting the PC to the wired network

and ping a known address Try a ___________________. Reload drivers

as necessary. Check the ______________________

settings on the client. Do they match the access point?

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Troubleshooting – poor connection

Check __________________ Check the ______________ on the client. Check for devices that might be causing

______________ (cordless phone, microwave oven etc).

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Troubleshooting – additional questions

Are all devices in place? Are they all powered on? Are wired links working correctly? Is there a neighboring access point using an

overlapping wave band? Are access points badly placed?