Wireless
Chapter 7
CCNA Exploration Semester 3
Modified by Profs. Ward
and Cappellino
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Topics
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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
Wireless-
Chp 7
VLANs
STP
VTP
Inter-VLAN
routing
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Wireless Review
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Wireless was covered in CSN208, therefore,
only new material will be presented here
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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
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Acts as:
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Router for use in ___________________
Ethernet ______________ and
wireless __________________________
Configuration on both the ____________________ is
necessary
Parameters:
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Mode refers to the 802.11a, b, g, or n
Configure SSID – what is the SSID?
Select channel within 2.4GHz band
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_________________________ should be set to use
_____________________________5
Channel Graph
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Different 802.11 Wireless Topologies…
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Ad Hoc
Basis Service Set (BSS)
Extended Service Set (ESS)
More to come on each of these…
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______________ topology
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WLAN operating with
_________________
_________________
Negotiate parameters
Independent basic
service set
Area covered is basic
service area (_____)
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__________________ topology
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_________________
Access point _________
____________________
___________________
for clients
Uses _________ mode
Area covered is basic
service area (_______).
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________________ topology
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_____________________
___________________
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
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Discovering a WLAN and connecting to it involves the
following components:
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________ - _________ used by the WLAN
networks to _____________________
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Access point may send out a beacon at regular intervals for
________________________
_________ - Frames _____________________
________________________
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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
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Components cont…
______________ One of three ___________
__________________________
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__________________________
____________________________
802.11 had two authentication mechanisms.
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________ (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
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Components cont…
_______________ - The process for _________
_________________________________________
__________________________
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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
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Implement a _____________________ prior to
construction of a WLAN
RF is a shared medium so the ______________
______________________ for RF
Place AP:
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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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___________________________
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Wireless Security/Protocol review
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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
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Possibilities for controlling access:
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___________________ - __________________________
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:
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To configure and test incrementally
Most access points have been _______________________
______________________ with the default settings
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________________________________!
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Basic Wireless Settings
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_______________ – 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.
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______________________________ on the
network.
_____________ can be enabled or disabled.
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More Basic Wireless Settings
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Radio Band –
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For best performance, keep the __________.
For Wireless-N devices only, select Wide 40MHz Channel.
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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.
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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
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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…
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Choose _____________________ if all client
devices are able to use it.
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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
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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?
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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 _____________
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Generally start with the ___________________
__________________ the TCP/IP stack…
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Check the ________________________ then
Update __________________
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Troubleshooting – no connectivity
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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
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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
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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?
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