CCNA Wireless Official Exam Certification Guide part 22 pdf

182 CCNA Wireless Official Exam Certification Guide
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Figure 10-8 Cisco 4400 Series Wireless LAN Controller
that can be installed in 6500 series switches or in Integrated Services Routers (ISR). There
are also appliance-based controllers, which include the 44xx series WLC as well as the
2100 series WLC. Which controller you require depends on how many APs you need de-
ployed. This can be anywhere from six to 300 access points per controller. This is a fixed
value and can’t be upgraded via licensing. If you need to support more APs, you need an-
other controller or a controller that supports more APs.
The Cisco 44xx Series WLC
The Cisco 44xx series Wireless LAN Controller, shown in Figure 10-8, is a standalone ap-
pliance.
It is designed to take up one rack unit. It has either two or four Gigabit Ethernet uplinks,
and they use mini-GBIC FSG slots. It can support 12, 25, 50, or 100 APs, depending on
the model. And it can support up to 5000 MAC addresses in its database.
The 4400 series has a 10/100 interface called a service port; it is used for SSH and SSL
connections for management purposes. The service port can be used for out-of-band man-
agement, but it is not required to manage the device. You can manage the device via the
controller’s logical management interface. There is also a console port that you can use to
connect via HyperTerminal or Teraterm Pro.
Depending on the country you are in, power requirements vary, but the chassis has two
power supply slots.
The controller code version used for the CCNA Wireless exam is version 5.x, and the AP
runs the same version. It’s actually a requirement that they run the same version, so when
an AP joins with a controller, the controller upgrades or downgrades the AP. The con-
troller upgrades four APs at a time. The 4400 series can support up to 100 access points.
So, a 4400 would upgrade ten APs at a time until they are all upgraded.
The 3750-G WLC
The 3750-G Wireless LAN Controller, shown in Figure 10-9, is integrated into a switch.
There are two assemblies—the WS-C3750G-24PS-E and the AIR-WLC4402-*-K9. The
two assemblies are connected to the SEPAPCB assembly, which has two Gigabit Ethernet

links connecting through SFP cables and two GPIO control cables. The major benefits of
this integration into the switching platform include the following:
■ Conservation of space
Key
Topi
c
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Chapter 10: Cisco Wireless Networks Architecture 183
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Figure 10-9 Cisco 3750-G Series Wireless LAN Controller
■ Integration of the backplane of the controller and switch
■ It saves ports
The 3750G is stackable with the 3750G switches, so you can stack it with other 3750s
that do not have the controller in them. The features it supports are the same as with the
4402 controllers; the only difference is the physical ports.
The Cisco WiSM
The Cisco WiSM, shown in Figure 10-10, is a services module that installs in the 6500 se-
ries switch or 7600 series router with the Cisco Supervisor Engine 720.
It has the same functionality as the 4400 series standalone controllers; the difference is
that it supports up to 300 APs. The WiSM supports 150 access points per controller, with
each blade having two controllers. Thus, you can have a total of 300 access points. You
can also cluster 12 of them into a mobility domain. This allows up to 7200 lightweight
APs in a mobility domain.
The Cisco 2106 WLC
The Cisco 2106 Wireless LAN Controller, shown in Figure 10-11, is also a single-rack unit
design with eight 10/100 Ethernet ports.
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Figure 10-10 Cisco WiSM
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184 CCNA Wireless Official Exam Certification Guide

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Figure 10-11 Cisco 2106 Series Wireless LAN Controller
Courtesy of Cisco Systems, Inc. Unauthorized use not permitted.
Figure 10-12 Cisco WLCM
It can support up to six primary access points. It has an RJ-45 console port and two RJ-45
ports that support PoE. It has nearly all the same features as the 4400 series controllers
but has eight built-in switch ports. You can expect to see this controller in a small branch
environment.
The Cisco WLCM
The Wireless LAN Controller Module (WLCM), shown in Figure 10-12, is designed for
the ISR routers. You would see this controller in a small office.
It has the same functionality as the 2106, but it does not have the directly connected AP
and console port. It supports six APs. The WLCM-Enhanced (WLCM-E) supports eight
or 12 APs, depending on which module you get.
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Chapter 10: Cisco Wireless Networks Architecture 185
Of course, some limitations apply. Most of the features are similar to the 4000 series:
■ LWAPP
■ RF control
■ The ability to be a DHCP server
■ Layer 2 security
The differences are things such as the following:
■ Lack of PoE ports
■ The number of APs supported
■ The LWAPP modes supported
For these reasons, you see the WLCM deployed in smaller branches.
Wireless LAN Controller Summary
Table 10-3 summarizes the Cisco Wireless LAN Controller models.
Wireless Network Management
In very large networks, a single wireless controller isn’t enough to manage all your APs.

This type of scenario might call for the Cisco Wireless Control System (WCS). The WCS
is a single point of management for up to 3000 lightweight APs and 1250 autonomous
APs. The WCS runs on a Windows or Red Hat Linux server. To scale beyond 3000 APs,
you would need the WCS Navigator. The WCS Navigator enables you to navigate between
different wireless control systems. It is a manager of managers, so to speak. You can use
the WCS Navigator to navigate between different WCS servers. You can then scale it up
to 30,000 APs in a single deployment and support up to 20 WCS deployments, all within
the WCS Navigator. There is also an additional appliance you can use, called the Cisco
Wireless Location Appliance, as shown in Figure 10-13.
Table 10-3 Controller Summary
Controller Mode Number of APs Supported Environment Deployed In
4400 Up to 100 Enterprise
3750G — Enterprise
WiSM 300 per WiSM, up to 3600 Enterprise (service module)
2106 6 Branch
WLCM 6 Branch
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Figure 10-13 Cisco Location Appliance
This is designed to do location tracking for Wi-Fi devices and RFID tags. It helps track
thousands of devices.
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Chapter 10: Cisco Wireless Networks Architecture 187
Table 10-4 Key Topics for Chapter 10
Key Topic Item Description Page Number
Paragraph from the section
“Features of the Cisco
Controllers”
Lists detailing access point and Cisco

controller responsibilities
172
Figure 10-2 The CUWN architecture 175
List from the section
“Access Points”
Description of the two types
of access points
176
Paragraphs from the section
“The Cisco 44xx Series WLC”
Description of the specifications
and capabilities of the Cisco
44xx series WLC
182
Exam Preparation Tasks
Review All the Key Topics
Review the most important topics from this chapter, denoted with the Key Topic icon.
Table 10-4 lists these key topics and the page number where each one can be found.
Complete the Tables and Lists from Memory
Print a copy of Appendix B, “Memory Tables” (found on the CD) or at least the section
for this chapter, and complete the tables and lists from memory. Appendix C, “Memory
Tables Answer Key,” also on the CD, includes completed tables and lists to check your
work.
Definition of Key Terms
Define the following key terms from this chapter, and check your answers in the glossary:
Lightweight AP, Autonomous AP, WLCM, WLCS
References
Cisco Wireless Services Module (WiSM): />Migrate to the Cisco Unified Wireless Network: />Cisco Unified Wireless Network: Secure Wireless Access for Business-Critical Mobility:
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This chapter covers the following subjects:

Understanding the Different LWAPP
Modes: A discussion of Layer 2 and Layer 3
LWAPP.
How an LWAPP AP Discovers a Controller: A
discussion regarding the process that an AP goes
through when finding a controller.
How an LWAPP AP Chooses a Controller and
Joins It: The process an AP takes when it chooses
a controller to join.
How an LWAPP AP Receives Its
Configuration: The process an AP takes when it
retrieves its configuration.
Redundancy for APs and Controllers: How to
provide redundancy for your APs.
The AP Is Joined, Now What?: A discussion on
the different functions an AP can perform.
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CHAPTER 11
Controller Discovery and Association
Table 11-1 “Do I Know This Already?” Section-to-Question Mapping
Foundation Topics Section Questions
Understanding the Different LWAPP Modes 1–3
How an LWAPP AP Discovers a Controller 4–5
How an LWAPP AP Chooses a Controller and Joins It 6–8
How an LWAPP AP Receives Its Configuration 9
Redundancy for APs and Controllers 10–11
The AP Is Joined, Now What? 12–14
When a lightweight AP boots up, it cannot function without a controller. In this chapter,
you will learn about the Lightweight Access Point Protocol (LWAPP) and the modes in
which it can operate. You will also learn about how an AP finds controllers on the net-

work, chooses one to join with, and then retrieves its configuration. In addition, you will
look at the ways to provide redundancy for your AP in the event that a controller goes
down. Finally, when an AP is joined with a controller, it can operate in certain modes that
can be used for different reasons. You will learn these operational modes and when they
are used.
You should do the “Do I Know This Already?” quiz first. If you score 80 percent or higher,
you may want to skip to the section “Exam Preparation Tasks.” If you score below 80 per-
cent, you should spend the time reviewing the entire chapter. Refer to Appendix A, “An-
swers to the ‘Do I Know This Already?’ Quizzes,” to confirm your answers.
“Do I Know This Already?” Quiz
The “Do I Know This Already?” quiz helps you determine your level of knowledge of this
chapter’s topics before you begin. Table 11-1 details the major topics discussed in this
chapter and their corresponding quiz questions.
1. What two modes can LWAPP operate in? (Choose two.)
a. Layer 2 LWAPP mode
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b. Joint LWAPP mode
c. Autonomous LWAPP mode
d. Layer 3 LWAPP mode
2. When LWAPP communication between the access point and the wireless LAN con-
troller happens in native, Layer 2 Ethernet frames, what is this known as?
a. EtherWAPP
b. Hybrid mode
c. Native mode LWAPP
d. Layer 2 LWAPP mode
3. What is the only requirement for Layer 3 LWAPP mode?
a. IP connectivity must be established between the access points and the WLC.
b. You must know the IP addressing on the AP.
c. Client devices must be in the same VLAN.
d. Each device in the Layer 3 domain must be on the same subnet.

4. Which state is not a valid state of an AP that is discovering and joining a controller?
a. Discover
b. Join
c. Image Data
d. Hybrid-REAP
5. What is the first step in a Layer 3 LWAPP discovery?
a. Priming
b. AP Join Request
c. Subnet broadcast of Layer 3 LWAPP discovery message
d. OATAP
6. AP-Priming is used for which of the following?
a. Prime an AP prior to bootup with complex algorithms
b. Deliver a list of controllers to the AP using a hunting process and discovery algo-
rithm
c. Perform basic setup of controller configurations delivered to the AP
d. Provision an AP over the air
7. Which of the following is not contained in a join response message?
a. Type of controller
b. Interfaces in the controller
c. Number and type of radios
d. AP name
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Chapter 11: Controller Discovery and Association 191
8. The join request message is sent to the primary controller only under what condition?
a. The controller is reachable.
b. The AP has an IP address.
c. The primary controller has low load.
d. The AP is primed.
9. If no primed information is available, what does the AP look for next when trying to

join a controller?
a. A master controller
b. A primer controller
c. A new controller
d. A new subnet
10. When an AP retrieves its configuration file, where is it applied?
a. RAM
b. ROM
c. NVRAM
d. Flash
11. How many backup controllers are in an N + 1 design?
a. 1
b. 2
c. 3
d. 4
12. Which method is considered the most redundant?
a. N + 1
b. N + N
c. N + N + 1
d. N * N + 1
13. Which AP mode can you use for site surveys?
a. Local mode
b. H-REAP mode
c. Bridge mode
d. Rogue Detection mode
14. In Monitor mode, which command can you use to change the value of the channels
monitored?
a.
config advanced channel-list
b. config advanced 802.11b channel-list monitor

c. config advanced 802.11b monitor channel-list
d. config advanced monitor channel-list
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