A+ Rapid Review

A+ Rapid Review Released

If you're preparing for the A+ exam, you might like to know that the new A+ Rapid Review book has been released.  This book is a a perfect supplement to one of the larger A+ books such as the CompTIA A+ Training Kit (Exam 220-801 and Exam 220-802).

At only 410 pages, the A+ Rapid Review book is much smaller than the 1024 pages of the A+ Training Kit and it doesn't go into as much depth in the A+ topics. However, the A+ Rapid Review book is invaluable in helping you understand what you know and what you don't know prior to walking into the testing center.

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The A+ Rapid Review book covers all of the objectives for the A+ exam and reinforces the key concepts. It includes nine chapters matched to the nine domains in the 220-801 and 220-802 exams.

Exam 220-801

• Chapter 1 PC Hardware
• Chapter 2 Networking
• Chapter 3 Laptops
• Chapter 4 Printers
• Chapter 5 Operational Procedures

Exam 220-802

• Chapter 6 Operating Systems
• Chapter 7 Security
• Chapter 8 Mobile Devices
• Chapter 9 Troubleshooting

As an example of what you'll see in the A+ Rapid Review book, here's an excerpt from Chapter 8 Mobile devices.

Chapter 8 Mobile devices

The Mobile Devices domain covers approximately 9 percent of the A+ 220-802 exam. It includes various mobile devices that are commonly used today, such as smartphones and tablets. As a PC technician, you need to be aware of the different types of operating systems used by these devices, how they can connect to a wireless network and the Internet, methods used to secure them, and how they can be synchronized. You also need to be aware of the hardware differences between tablets and laptops, such as what can be serviced or upgraded on each.

This chapter covers the following objectives:

• Objective 3.1: Explain the basic features of mobile operating systems
• Objective 3.2: Establish basic network connectivity and configure email
•  Objective 3.3: Compare and contrast methods for securing mobile devices
• Objective 3.4: Compare and contrast hardware differences in regards to tablets and laptops
• Objective 3.5: Execute and configure mobile device synchronization

Objective 3.1: Explain the basic features of mobile operating systems

The CompTIA exam focuses on the Android and iOS operating systems used on many mobile devices. You need to know which operating system is used on which devices, and where users can purchase apps for these devices. This objective specifically mentions the accelerometer and gyroscope used in many devices and how they are used by different apps. Touch devices can sometimes require screen calibration, and you should understand what this is and when it is needed. Last, you need to know what is meant by terms global positioning system (GPS) and geotracking, and how they can be used with location services.

Exam need to know...

• Android vs. iOS For example: Which operating system is open source? Where can apps be purchased for devices using the iOS operating system?
• Screen orientation and calibration For example: What determines whether a tablet is moving and how quick it is moving? What hardware is required to maintain screen orientation?
• GPS and geotracking For example: What is geotracking? What is a benefit of location services?

Android vs. iOS

Mobile devices created and sold by Apple use the iOS operating system. Many other mobile devices use the Android operating system, which is closely associated with Google.

NOTE While the Windows 8 phone and Windows 8 tablets are in use, they aren’t currently included in the objectives for the CompTIA exams.

True or false? The Android operating system is an open source operating system.

Answer: True. The Android operating system is a Linux-based operating system, which is open source. 

Many different hardware companies use the Android operating system on devices they create and sell. They don’t have to pay Google or anyone else to use the operating system. In contrast, only Apple makes hardware devices using the iOS operating system. No other company is authorized to use it on non-Apple devices. The difference between open source and closed source software is defined as follows:

• Open source software is freely available to anyone. Developers can modify and redistribute the code without paying anyone else for the license to use it.
• Closed source software (also called vendor-specific software) is proprietary to a company and not available without a license to use it.

EXAM TIP Ensure that you know the difference between open source and closed source software. Android is open source software, and iOS is closed source or vendor-specific software.

True or false? You can purchase iOS-based applications only from Apple’s App Store.

Answer: True. Apple tightly controls all software used on Apple devices, and this software can be purchased only from Apple’s App Store.

A benefit of the App Store is that the applications are free from viruses. Apple screens all applications before making them available for purchase. If a virus is discovered, it can be immediately removed from the store. Additionally, if a developer does upload a virus, Apple knows the developer’s identity and can take immediate action against the developer.

Android-based apps are available through Google Play (previously called Android Marketplace), and Google controls the apps available here. However, there are additional locations where users can purchase Android apps. For example, Amazon includes a section where you can buy Android-based apps.

EXAM TIP Apps for Apple devices are purchased only through the Apple App store. Users can access the App store directly from any Apple device. Apps for Android-based systems are available through Google Play primarily, but they can also be purchased through other sources.

MORE INFO You can visit the Google Play site here: https://play.google.com/store. Microsoft also has a store where apps can be purchased for mobile devices, which you can view here: http://www.windowsstore.com/.

Screen orientation and calibration

Mobile devices such as tablets and smartphones can automatically sense their orientation. They can modify the display for the user, such as change from portrait mode to landscape mode based on how the user is holding the display.

True or false? Tablets use an accelerometer and a gyroscope to determine the position of the device. 

Answer: True. Many devices have a single chip with an accelerometer and a gyroscope used to determine the position of the device.

The accelerometer/gyroscope chip sends an output to the operating system and applications. If the feature is enabled in the operating system and supported by the app, the display is automatically adjusted when the user changes the orientation of the device. For example, a user can be reading an eBook in an app using portrait mode, with the device held so that the height is greater than the width. If the user repositions the device so that the width is greater than the height, the device automatically switches to landscape mode. 

Optionally, you can disable the feature so that the display remains constant no matter how the device is held. For example, you can enable Rotation Lock on an iPad to lock the display.

True or false? An accelerometer can measure how fast a tablet is moving in a given direction.

Answer: True. The accelerometer measures velocity or speed of the tablet in a given direction. This is often used with games on tablet devices.

EXAM TIP Accelerometers and gyroscopes are embedded into mobile devices to determine the device’s position. The gyroscope detects how the user is holding the device so that the screen orientation can automatically be adjusted to portrait or landscape mode. The accelerometer detects when the device is moved and how fast it is moving, a feature that is used in some games and apps.

True or false? If the device cannot determine its position, you can sometimes recalibrate it by moving the entire device in a figure 8 pattern.

Answer: True. In some cases, the device can no longer determine its position. You can hold the device with both hands in front of you and move it in a figure 8 pattern to recalibrate it.

EXAM TIP Not all mobile devices include a gyroscope. If you find that a device is not automatically switching between landscape and portrait mode, it could be because the device doesn’t have a gyroscope or because the feature is disabled.

Can you answer these questions?

You can find the answers to these questions at the end of this chapter.

1. Is the Android operating system closed source or open source?
2. Where are apps for devices running iOS purchased?
3.What is the purpose of the gyroscope and accelerometer in a mobile device?

Realistic practice test questions for the Network+ exam. Available through LearnZapp on your mobile phone

Answers

This section contains the answers to the “Can you answer these questions?” sections in this chapter. 

Objective 3.1: Explain the basic features of mobile operating systems

1. The Android operating system is an open source operating system based on the Linux operating system.
2. iOS is the Apple operating system, and apps can be purchased at Apple’s App store.
3. The gyroscope determines the screen orientation and can be used to modify the display when the user changes the orientation of the device. The accelerometer determines how fast a device is moving.

Summary

If you want a quick review of the concepts you'll be tested on in the A+ exams, check out the A+ Rapid Review book. It provides you with a quick, concise review of the objectives and reminds of the testable concepts.

Security+ WAP Performance Based Questions

If you’re planning on taking the Security+ exam you can expect to see some Security+ WAP performance based questions. These questions expect you to know how to configure a wireless access point (WAP). Even if you've done it once or twice, it might not be fresh in your mind so it's good to review the topics. 

Networks commonly use wireless access points (WAPs) and configuring security with them is an important skill to have. CompTIA stresses this on both the Network+ and Security+ exams. You should be able to configure basics such as:

• Change the SSID
• Enable/disable SSID broadcast
• Enable MAC address filtering
• Configure security such as WPA and WPA2
• Configure WPA/WPA2 Enterprise

Ideally, you should get your hands on a WAP or a wireless router used in many homes and small offices home offices (SOHOs). They are easily accessible and aren't expensive and the experience configuring it is valuable for on the job and the exam. The following sections show how to configure a Cisco M20 wireless router. All devices aren't exactly the same, but you'll find similar settings if you click around.

Pass the Security+ exam the first time you take it: CompTIA Security+: Get Certified Get Ahead: SY0-301 Study Guide

Accessing the Administration Page

Wireless access points have web pages you can use to configure settings. You can access the administration pages by entering the IP address of the access point into the web browser. The IP address of most access points is either 192.168.1.1 or 192.168.0.1.

After entering the IP address, you're prompted to enter the name and password for the administrator account. These also have defaults such as "admin" for the administrator account and "admin" for the password but it is highly recommended to change the defaults.

Change the SSID

The service set identifier (SSID) is the name of the network.  It is a case sensitive string of up 32 characters. Devices come with a default SSID and it's recommended to change the SSID from the default as a best practice.

The following figure shows the basic setting for SSID. On this WAP, you have to select the Wireless main menu and the Basic Wireless Settings submenu.  You then enter the desired network name for in the Network Name (SSID) text box. In the figure, I used the SSID of MyHomeWAP but any name with 32 characters can be used.

Enable/Disable SSID Broadcast

You can hide a wireless network from casual users by disabling SSID broadcast and a performance based question might require you to select one of these settings. The following figure shows how this is done on a sample access point. It's important to realize that even if you disable SSID broadcast, attackers can still discover the SSID with a wireless sniffer. In other words, disabling SSID broadcast doesn't provide any real security. You can read more about in the  Disable SSID Broadcast or Not? blog.

Enable MAC Address Filtering

Another configuration you might need to implement for Security+ WAP performance based questions is media access control (MAC) address filtering. The MAC address is assigned to the network interface card (NIC) when it is manufactured and you can use it to identify specific devices. When used within a MAC address filter, you can restrict access to the wireless network to specific devices based on their MAC address.

As an example, the following figure shows a MAC address filter configured on a wireless access point.  You can see that it is enabled and configured to "Permit PCs listed below to access the wireless network." The wireless client list includes five MAC addresses. Devices with these MAC addresses will be allowed access to the network, but other devices will be blocked.

This setting isn't restricted to only PCs. Any wireless device has a MAC address including tablet devices and smartphones.

You can also configure a MAC address filter to block specific devices. For example, if your neighbor is using your access point to access the Internet, you can block his system using his MAC address. You would select the first setting "Prevent PCs listed below from accessing the wireless network" and enter the MAC address of his system.

Configure Security Such as WPA and WPA2

You also need to know how to configure basic security setting such as Wi-Fi Protected Access (WPA) or Wi-Fi Protected Access version 2 (WPA2). You can typically select the appropriate setting from a drop down box and then enter the appropriate passphrase. The settings entered on the access point must be used on all devices that connect to the access point.

 The following figure shows these settings.
 

Configure WPA/WPA2 Enterprise

Both WPA and WPA2 operate in either Personal or Enterprise modes. Most home and small business networks use Personal mode using a passphrase or password.

Larger enterprises add additional security to WAPs with WPA Enterprise or WPA2 Enterprise.  Enterprise mode provides additional security by adding an authentication server and requiring each user to authenticate through this server. Authentication requires all users to prove their identities and a common way authentication is accomplished is with a username and password. A user claims an identity with a username and proves the identity with a password.

Enterprise mode requires an 802.1x server typically configured as a Remote Authentication Dial-In User Service (RADIUS) server, which is configured separately from the access point. The RADIUS server has access to the user’s authentication credentials and can verify when a user has entered authentication information correctly.

The following figure shows the configuration for an access point using WPA2 Enterprise. After selecting WPA2 Enterprise from the drop down box, the  selections change. You then need to enter the IP address of the RADIUS server and the shared secret configured on the RADIUS server. The default port for RADIUS is 1812 and you only need to change this if the RADIUS server is using a non-default port.  

Other Security+ Resources

• CompTIA Security+: Get Certified Get Ahead: SY0-301 Study Guide
• Security+ Audio Files Now Available
• Kindle Version of Security+ Study Guide Now Available
• Security+ Practice Test Questions for Your Mobile Phone

Security+ WAP Performance Based Questions Summary

You can expect to see some Security+ WAP performance based questions on the Security+ exam. These questions expect you to know how to configure a wireless access point (WAP) including the SSID, MAC address filtering, and security settings such as WPA2 Personal or WPA2 Enterprise.

Security+ Controls

If you’re planning on taking the Security+ exam you can expect to see some Security+ Controls questions. Objectives for the Security+ exam specifically identify the following three control types:

• Technical
• Management
• Operational

Controls are also identified based on their function. The three primary functions of controls are:

• Preventative
• Detective
• Corrective

Material from this blog comes from the top selling CompTIA Security+: Get Certified Get Ahead: SY0-301 Study Guide. Pass the Security+ exam the first time you take it.

If you pursue other security certifications, such as with SSCP or CISSP exams, you'll need to dig into controls a little deeper. However, the Security+ exam doesn't go too deep with this topics. As an example, check out these practice test questions.

Security+ Controls Practice Test Questions

Of the following choices, what type of control is least privilege?
A. Corrective
B. Technical
C. Detective
D. Preventative
Which of the following is a preventative control that can prevent outages due to ad-hoc configuration errors? A. Security audit B. Least privilege C. Change management plan D. A periodic review of user rights
Answers at the end of this blog

Security+ Control Objectives

Controls are mentioned in the following Security+ objectives:
2.1 Explain risk related concepts

• Control types
  • Technical
  • Management
  • Operational

2.2 Carry out appropriate risk mitigation strategies

• Implement security controls based on risk

3.6 Analyze and differentiate among types of mitigation and deterrent techniques

• Detection controls vs. prevention controls
  • IDS vs. IPS
  • Camera vs. guard

Technical Controls

A technical control is one that uses technology to reduce vulnerabilities. An administrator installs and configures a technical control, and the control then provides the protection automatically. The following list provides a few examples of technical controls:

• Least Privilege. The principle of least privilege is an example of a technical control. It specifies that individuals or processes are granted only the rights and permissions needed to perform their assigned tasks or functions, but no more.
• Antivirus software. Once installed, the antivirus software provides protection against infection.
• Intrusion detection systems (IDSs). An IDS can monitor a network or host for intrusions and provide ongoing protection against various threats.
• Firewalls. Firewalls restrict network traffic going in and out of a network.

Management Controls

Management controls are primarily administrative in function. They use planning and assessment methods to provide an ongoing review of the organization’s ability to reduce and manage risk. Some management controls are:

• Risk assessments. These help quantify and qualify risks within an organization so that they can focus on the serious risks. For example, a quantitative risk assessment uses cost and asset values to quantify risks based monetary values. A qualitative risk assessment uses judgments to categorize risks based on probability and impact.
• Vulnerability assessments. A vulnerability assessment attempts to discover current vulnerabilities. When necessary, additional controls are implemented to reduce the risk from these vulnerabilities.

Operational Controls

Operational controls help ensure that day-to-day operations of an organization comply with their overall security plan. Operational controls include the following families:

• Awareness and training. The importance of training to reduce risks cannot be overstated. Training helps users maintain password security, follow a clean desk policy, understand threats such as phishing and malware, and much more.
• Configuration management. Configuration management often uses baselines to ensure that systems start in a secure, hardened state. Change management helps ensure that changes don’t result in unintended configuration errors.
• Contingency planning. Chapter 9 presents several different methods that help an organization plan and prepare for potential system outages. The goal is to reduce the overall impact on the organization if an outage occurs.
• Media protection. Media includes physical media such as USB flash drives, external and internal drives, and backup tapes.
• Physical and environmental protection. This includes physical controls such as cameras, door locks, and environmental controls such as heating and ventilation systems.

Pass the Security+ exam the first time you take it: CompTIA Security+: Get Certified Get Ahead: SY0-301 Study Guide

Controls Based on Functions

Many controls are identified based on their function as opposed to the type of control. The three primary functions of controls are preventative, detective, and corrective.

Preventative Controls

Preventative controls attempt to prevent an incident from occurring. The goal is to take steps to prevent the risk. Some examples include:

• Security guards. Guards act as a deterrent and provide a preventative security control. For example, an attacker may attempt social engineering to fool a receptionist, but is less likely to attempt these techniques, or succeed, when guards protect an access control point.
• Change management. Change management (introduced as an operational control) ensures that changes don’t result in ad-hoc (or as-needed) configuration errors. In other words, instead of administrators making changes on the fly, they submit the change to a change management process.
• Account disablement policy. Most organizations ensure that user accounts are disabled when an employee is terminated. This ensures that these accounts are not used by the ex-employee or by anyone else.
• System hardening. Various methods ensure that a system is more secure from its default configuration. This includes removing and disabling unneeded services and protocols, keeping the system up to date, and enabling firewalls.

Detective Controls

Detective controls are designed to detect when a vulnerability has been exploited. A detective control can’t predict when an incident will occur, and it can’t prevent it. However, it can discover the event after it’s occurred. Some examples of detective controls are:

• Security audit. Security audits can examine the security posture of an organization. For example, a password audit can determine if the password policy is ensuring the use of strong passwords. Similarly, a periodic review of user rights can detect if users have more permissions than they should.
• Video surveillance. A closed circuit television (CCTV) system can record activity and detect what occurred. It’s worth noting that video surveillance can also be used as a preventative control since it can act as a deterrent.

Corrective Controls

Corrective controls attempt to reverse the impact of an incident or problem after it has occurred. Some examples of corrective controls are:

• Active IDS. Active intrusion detection systems (IDSs) attempt to detect attacks and then modify the environment to block the attack from continuing.
• Backups and system recovery. When data is lost, a backup ensures that the data can be recovered. Similarly, when a system fails, system recovery procedures ensure it can be recovered. Chapter 9 covers backups and disaster recovery plans in more depth.

Security+ Controls Practice Test Question Answer

Of the following choices, what type of control is least privilege?
A. Corrective
B. Technical
C. Detective
D. Preventative

Bis correct. The principle of least privilege is a technical control and ensures that users have only the rights and permissions needed to perform the job, and no more. A corrective control attempts to reverse the effects of a problem. A detective control (such as a security audit) detects when a vulnerability has been exploited.A preventative control attempts to prevent an incident from occurring.

Which of the following is a preventative control that can prevent outages due to ad-hoc configuration errors?

A. Security audit
B. Least privilege
C. Change management plan
D. A periodic review of user rights

D is correct. A vulnerability assessment is a management control and attempts to discover weaknesses in systems. A corrective control attempts to reverse the effects of a problem. A detective control (such as a security audit) detects when a vulnerability has been exploited. A technical control (such as the principle of least privilege) enforces security using technical means.

Resources

• CompTIA Security+: Get Certified Get Ahead: SY0-301 Study Guide
• Excerpt of CompTIA Security+ Get Certified Get Ahead Study Guide
• Security+ Audio Files Now Available
• Kindle Version of Security+ Study Guide Now Available
• Security+ Practice Test Questions for Your Mobile Phone
• SY0-301 Security+ Study Guide on Amazon

Security+ Controls Summary

When preparing for the Security+ exam, ensure you're aware of the Security+ Controls mentioned in the objectives. This includes: Technical Controls, Management Controls, and Operational Controls. You should also be aware of the three primary functions of controls: Preventative, Detective. and Corrective.

IT Certification Path for Network Administrators

Aspiring IT professionals frequently ask me questions like “How can I get into an IT job?” and “What is the best IT certification path for network administrators?” Unfortunately, there isn't a one-size-fits-all answer because there are so many variables, such as how much knowledge you start with and what type of jobs are available where you live.

However, if you are focused on landing an IT job and you‘re willing to take the time to master the materials, you can earn several certifications that will make you highly desirable as a network administrator, one of the industry’s most essential and opportunity-rich positions. Learn the material, earn the certifications, and you’ll have an opportunity to shine at network administration job interviews.

First, what is a network administrator? Most people define a network administrator as someone that maintains hardware and software on a computer network. In a large organization, the network administrator is a mid-level IT worker focused primarily on maintaining networking components. However, in smaller organizations, the network administrator is also responsible for desktop support for end-users, maintaining servers, and managing any other devices connected to the network.

In this article, I've divided the IT certification path for network administrators  into three categories:

• Foundation certifications: These CompTIA certifications are vendor-neutral and provide a solid knowledge base for any path to becoming a network administrator.
• Cisco certifications: These credentials are valuable for administrators that manage Cisco’s widely-used network devices, such as routers and switches.
• Microsoft certifications: These certificates are key for administrators that provide network administration services at both the desktop and server level.

People commonly want to know how long it’ll take to complete these certifications so I've given some common study time estimates. These guidelines assume you have a job but you’re still able to study regularly to master the concepts. Someone that is unemployed and spending 12 hours a day studying can complete these certifications much quicker. In contrast, someone with a full time job that regularly requires overtime might need more time.

more...

CompTIA Network+ Wireless Topics

The CompTIA Network+ Wireless Topics (A Get Certified Get Ahead Kindle Short) is now available. This Kindle short includes a chapter on Network+ Wireless topics and 55 realistic questions with full explanations. Only $2.99.

In case you don't know it, you can read Kindle books no just about any device with freely available Kindle apps.

Part of Upcoming CompTIA Network+: Get Certified Get Ahead Study Guide

Many of you might now that I’m in the process of writing a Network+ book using the same format as the top selling CompTIA Security+: Get Certified Get Ahead Study Guide.

However, instead of waiting until the entire book is complete, I’ve decided to post some chapters on Amazon in the Kindle format. I’m calling these “Kindle Shorts” because they aren’t full books but they do have a lot of relevant content.

The first “Kindle Short” is on wireless topics and covers all of the CompTIA Network+ Wireless objectives:

• 2.2 Given a scenario, install and configure a wireless network.
• 2.4 Given a scenario, troubleshoot common wireless problems.
• 3.3 Compare and contrast different wireless standards.
• 5.1 Given a scenario, implement appropriate wireless security measures.
• 5.4 Explain common threats, vulnerabilities, and mitigation techniques.

If you want another perspective on the wireless objectives to ensure you have mastered these topics, check out this book.

Part of Kindle Owners' Learning Library

This Kindle short is available for free to Kindle device owners that have an Amazon Prime Membership as a part of the Kindle Owner's Lending Library.

Other Network+ Study Resources

If you're studying for the Network+, check out these additional resources:

• List of blogs on Network+ topics (includes links to free practice test questions)
• CompTIA Network+ N10-005 Practice Test Questions (Get Certified Get Ahead)
• Practice test questions for your mobile device
• Free practice test questions regularly posted to the Get Certified Get Ahead Facebook page

Network+ and Wireless Standards

If you're preparing for the Network+ exam, you probably know that a good portion includes wireless topics including wireless standards. If you can master some basic facts on wireless standards, you'll be able to ace many Network+ questions without any trouble at all.  Another post covered Network+ and Wireless Encryption topics.

Several objectives address wireless standards directly:

• 2.2 Given a scenario, install and configure a wireless network. (This objective includes "Frequencies", "Wireless standards", and "Compatibility (802.11 a/b/g/n)"
• 2.4 Given a scenario, troubleshoot common wireless problems. (This objective includes "Configurations", and "Incompatibilities")
• 3.3 Compare and contrast different wireless standards. (This objective includes "802.11 a/b/g/n standards")

Network+ Practice Test Questions

Here are a couple of practice test questions you can use to check your knowledge of the Network+ wireless standards.

Q1. You are tasked with configuring a wireless network that can support legacy devices and operate on both 2.4 GHz and 5 GHZ. What would you use?

A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Q2. Which of the following wireless standards operates at 5 GHz and has a maximum speed of 54 Mbps?

A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Q3. Which of the following wireless standards supports multiple transceivers within a single WAP?

A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Over 275 realistic practice test questions available in the
CompTIA Network+ N10-005: Practice Test Questions (Get Certified Get Ahead) Kindle book.
Only $9.99 . Free Kindle apps available for any platform.

802.11a

The 802.11a standard is one of the early wireless standards and it was released in 1999. It uses Orthogonal frequency-division multiplexing (OFDM) in the 5 GHz frequency range. One of the reasons 5 GHz was selected is to avoid the interference in the noisier 2.4 GHz frequency range. The original specification had 12 non-overlapping channels that could be used compared with the three non-overlapping channels supported in 802.11b and 802.11g. It also uses dynamic frequency selection (DFS) allowing the device to automatically switch channels when it detected interference. Radar technologies use portions of the 5 GHz range so DFS is useful to avoid interference from radar sources.

Unfortunately, 802.11a signals are much more susceptible to interference from physical objects such as walls and have the lowest transmission distance of the four standards. The maximum range of 802.11a is often quoted as 30 meters (about 98 feet) but this can be affected by the signal strength of the wireless access point (WAP) and interference sources.

It’s rare to see new 802.11a wireless devices today. However, you might run across some legacy devices using 802.11a.

802.11b

The 802.11b standard came out at about the same time as 802.11a. It operates in the 2.4 GHz frequency range, has a maximum speed of 11 Mbps, and a mildly longer range than 802.11a. Compared with 802.11a, 802.11g, and 802.11n, it is the only standard that uses Direct-sequence spread spectrum (DSSS). 802.11b uses 22 MHz wide channels with some regions allowing as many as 13 channels. Commonly used non-overlapping channels are 1, 6, and 11. While 802.11b was more popular than 802.11a, it is rarely used today.

802.11g

The 802.11g standard was released in 2003 and up until the release of 802.11n has been the most popular. It supports speeds up to 54 Mbps, operates in the 2.4 GHz range and has a slightly longer range than 802.11b. It uses 20 MHz wide channels and channels 1, 6, and 11 are commonly used as non-overlapping channels. As with 802.11a and 802.11n, 802.11g uses OFDM.

One significant difference with 802.11g over 802.11a and 802.11b is that it supports channel bonding. This was also known as Super G and wasn’t supported by all wireless devices. When supported, Super G increased the maximum throughput from 54 Mbps to 108 Mbps.

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802.11n and MIMO

The newest standard is 802.11n and it is proving to be far superior to the three previous 802.11 standards. It is the fastest and supports speeds up to 600 Mbps and can operate in both the 2.4 GHz and 5 GHz frequency spectrums. It also has the longest range with distances up to 70 meters. As with 802.11a and 802.11g, it uses OFDM.

A significant difference with 802.11n is the use of a smart antenna technology called multiple input multiple output (MIMO) to achieve faster speeds. MIMO includes multiple antennas and transceivers to simultaneously transmit and receive data over multiple streams. MIMO can include as many as four streams of communication with each stream supporting up to 150 Mbps. When four streams are used, it supports connections up to 600 Mbps.

The multiple antennas used with MIMO provide diversity gain which improves the overall link reliability. These streams are sent separately in a process called spatial multiplexing.

Another difference with 802.11n is that it supports 20 MHz channels just like 802.11g and it also supports 40 MHz channels for greater throughput. When 40 MHz channels are used it is often referred to as channel bonding.

Many wireless networks have a combination of both 802.11g and 802.11n devices. An 802.11n WAP can support both standards. Also, they can be configured to use only 2.4 GHz or a combination of 2.4 GHz and 5 GHz.

If you create a network using all 802.11n devices and they all support 5 GHz, you can configure the WAP to use only 5 GHz. Because this frequency band has less interference you can often get much better throughput. However, before switching over, it’s important to verify that all the devices support 5 GHz because it isn’t required. Many vendors create 802.11n wireless devices using only 2.4 GHz to make the devices more affordable.

Realistic practice test questions for the Network+ N10-005 exam and more.
Available through LearnZapp on your mobile devices.

Answer to Practice Test Question 1

Q1. You are tasked with configuring a wireless network that can support legacy devices and operate on both 2.4 GHz and 5 GHZ. What would you use?
A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Answer 1. D is correct. Only an 802.11n network will operate on both 2.4 GHz and 5 GHz frequencies. 802.11n networks can also support older (legacy) devices because it is backwards compatible with earlier wireless standards.

802.11a only uses 5 GHZ.

802.11b and 802.11g only uses 2.4 GHz.

Answer to Practice Test Question 2

Q2. Which of the following wireless standards operates at 5 GHz and has a maximum speed of 54 Mbps?
A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Answer 2. A is correct. The 802.11a standard operates at 5 GHz and has a maximum speed of 54 Mbps.

802.11b and 802.11g both operate at 2.4 GHz.

802.11n uses 2.4 GHz and 5 GHz but it has a maximum transfer rate of 600 Mbps, not 54 Mbps.

Answer to Practice Test Question 3

Q3. Which of the following wireless standards supports multiple transceivers within a single WAP?
A. 802.11a
B. 802.11b
C. 802.11g
D. 802.11n

Answer 3. D is correct. 802.11n uses multiple input multiple output (MIMO) technologies and MIMO supports multiple transceivers within a single wireless access point (WAP).

MIMO is not supported in 802.11a, 802.11b, or 802.11g.

Summary

Here's a short summary of some of the key characteristics with each of the different wireless standards.

802.11a

• Maximum speed of 54 Mbps
• Operates in the 5 GHz frequency range
• Shortest distance - can travel about 35 meters (about 115 feet)

802.11b

• Maximum speed of 11 Mbps
• Operates in the 2.4 GHz frequency range
• Can travel about 35 meters (about 115 feet)

802.11g

• Maximum speed of 54 Mbps
• Operates in the 2.4 GHz frequency range
• Can travel about 38 meters (about 125 feet)
• Supports channel bonding with Super G (combines two 54 Mbps channels to give 108 Mbps max speed)

802.11n

• Maximum speed of 600 Mbps
• Operates in the 2.4 GHz and 5 GHz frequency ranges
• Longest distance - can travel about 70 meters (about 230 feet)
• Uses MIMO supporting multiple transceivers within a single wireless access point
• Can use 40 MHz channels (referred to as channel bonding

A+ Mobile Apps on Android

Learnzapphas recently released practice test question mobile apps for the A+ 220-801 and 220-802 exams on Android devices. If you enjoy studying while on the go, these apps provide you with an easy to use tool where you can squeeze in some study time whenever you have a spare moment.

This release includes some great improvements to their existing mobile apps which improved their performance and the user interface. They have also created some great bundles for people planning on taking multiple CompTIA exams such as Network+ and Security+.

If you search Google Play with "LearnZapp" you'll find all of their offerings including the following new items:

• CompTIA A+ 220-801
• CompTIA A+ 220-802
• CompTIA A+ Bundle (801 and 802)
• CompTIA Value Pack (801, 802, Security+ and Network+)

Other apps that have been upgraded with the new platform are:

• CompTIA Security+
• CompTIA Network+
• CompTIA Bundle (Security+ and Network+)

All of these apps are also available for Apple devices such as iPads and iPhones. Search the App Store with "LearnZapp" and you'll see a similar listing.