A guide to software troubleshooting from a CompTIA A+ perspective
Continuing the examination of changes coming in the CompTIA A+ exams as they are updated, this month we look at the domain Software Troubleshooting. It constitutes 24 percent of the 220-902 certification exam and covers a wide breadth of topics. While the Microsoft Windows operating systems being tested upon are only stated to include Windows 7, Windows Vista, and Windows 8/8.1, within this category there are such topics as “Missing NTLDR,” which implies that you should know a little something about Windows XP as well.
While there is always the opportunity for topics to change, there are currently four subdomains:
4.1 — Given a scenario, troubleshoot PC operating system problems with appropriate tools.
4.2 — Given a scenario, troubleshoot common PC security issues with appropriate tools and best practices.
4.3 — Given a scenario, troubleshoot common mobile OS and application issues with appropriate tools.
4.4 — Given a scenario, troubleshoot common mobile OS and application security issues with appropriate tools.
Since the latter two are the newest and most changed from the -800 series of exams, they are what we will focus on this time around.
Troubleshooting Mobile Issues
As mobile devices have been rapidly replacing the desktop and laptop machines that used to rule the workplace, the equipment an administrator must maintain has now evolved to cover a plethora of options. This section focuses on common mobile OS and application issues and some of the tools that can be used to work with them. A subsequent section will look at the same topics with more of a focus on security.
Common symptoms of problems with mobile OS and applications include:
Dim display: Light can quickly drain a battery on a mobile device and thus most of them include the ability to dim the display both manually and automatically after a period of inactivity. While you normally want these actions, if the settings are incorrect, the screen can be too dim to work with under working conditions. Check the settings on the device to see if it possible to brighten the screen and/or keep it from auto dimming within a short period of time.
Intermittent wireless: There are a number of causes why intermittent wireless can occur, but the two most common are lack of a good signal and interference. Increasing the number of repeaters, or being closer to them, can address the lack of a good signal. Interference can be addressed by reducing the number of devices competing for the same channel.
No wireless connectivity: A common cause for lack of wireless connectivity is for a device to be in airplane mode. Make sure that your device is not in that mode, and do a hard reboot if necessary.
No Bluetooth connectivity: Lack of Bluetooth connectivity is often caused when a device is not turned on and/or has an improper setting for discoverabilty. Make sure that the device is turned on and discoverable (checking manufacturer’s documentation if necessary).
Cannot broadcast to an external monitor: Connecting a mobile device, such as a phone, to a television or monitor should not be problematic as long as autodetection is working. If autodetection is disabled, or just not working, then you may need to configure the output device manually.
Non-responsive touchscreen: If your touchscreen becomes nonresponsive with a mobile device, try some basic steps: first, remove any added case or screen protector that may have been put on your device and then clean the screen (use a lint-free cloth). Next, unplug your device and restart it (forcing it to restart, if necessary).
Apps not loading: If an app does not load, try rebooting (forcing it to restart, if necessary). If that does not work, attempt to reload the app and be sure to check the vendor’s site for any similar problems (and solutions) encountered by others.
Slow performance: Slow performance is often related to RAM. Look for any apps that are running which can be closed, and add more RAM if possible.
Unable to decrypt email: Mail decryption depends upon certificates, and problems can occur when those certificates expire or you have a configuration problem (which can accompany upgrades). To address the problem, try reimporting s/mime certificates and deleting/importing the s/mime from the source
Extremely short battery life: Batteries never last as long as you would like. Apple defines battery life as the amount of time a device runs before it needs to be recharged (as opposed to battery lifespan, which is the amount of time a battery lasts before it needs to be replaced). Tips for increasing battery life include keeping OS updates applied (they may include energy saving patches), avoiding too high or too low ambient temperatures, letting the screen automatically dim, and turning off location-based services. You should also disconnect peripherals and quit applications not in use (Wi-Fi, for example, uses power when enabled, even if you are not using it to connect to the network).
Overheating: When most mobile devices get too warm, they will tell you that they need to cool down before they can continue to be used and they will automatically take measures to protect themselves (turning off features, closing apps, and so on). One of the best ways to avoid overheating is to avoid ambient temperatures that are too hot or too cold: avoid having the device in direct sunlight for extended time periods, in a hot car on a summer day, or on top of a heat source. When the device does overheat, you can often help it cool down quicker by removing any protective case that may be there—and putting it back on later.
Frozen system: If the system is frozen — not responding to a single thing — try to force a restart. For example, pressing and holding the Sleep/Wake and home buttons an iPhone for at least 10 seconds until you see the Apple logo does this. If the restart does not work, try plugging the device in and letting it charge (an hour or more is recommended) and try restarting again.
No sound from speakers: Occasionally, a device can be unknowingly put into silent mode, and this will keep sound from coming to the speakers, headphones, or other connected devices. When troubleshooting, always check to see that silent mode is not enabled and restart the device if necessary.
Inaccurate touchscreen response: To solve problems with inaccurate touchscreen responses, start by cleaning the screen, as discussed earlier, and rebooting the device.
System lockout: Being locked out of a system can be a frustrating experience. The lockout can be the result of the device being disabled, forgetting the passcode, or any of a number of other possibilities. Apple outlines how to approach this for the iPhone, iPad, or iPod touch at: https://support.apple.com/en-us/HT204306
There are a number of tools — really just approaches or techniques — that can be used to approach these common problems. These include:
Hard reset: A hard reset should always be done as a last resort. With Apple’s iPhone, iPad, or iPod touch, forcing a restart on the device is done by pressing and holding the Sleep/Wake and Home buttons for at least 10 seconds until you see the Apple logo.
Soft reset: Not as forceful as a hard reset, a soft reset keeps the data of running applications. With Apple’s iPhone, iPad, or iPod touch, press and hold the Sleep/Wake button until the red slider appears, and then drag the slider to turn the device off. Next, press and hold the Sleep/Wake button again until you see the Apple logo.
Close running applications: With most smartphones, iPads, and so on, you do not need to close running applications unless there is a problem. When there is, press the Home button two times and then find the desired application (sliding between choices, if necessary). Hold your finger on the application for 2 seconds, and the icon for it will start to shake with a minus symbol on the top left of it. Press the icon again, and it will close the app.
Reset to factory default: When you need to get to a safe state — such as when you are disposing of a device or assigning it to a new user — you can reset it to factory default settings. To do this, tap Settings and then General. Scroll down until you see the Reset option and choose it. Tap Erase All Content and Settings. At this point, the iPhone or iPad will ask you to confirm the reset, and when you tap OK it will start the process.
Adjust configurations/settings: Configurations and settings need to be personalized to the user using the device. Other than for apps, choosing Settings on the device usually does this, followed by finding the areas that you want to modify and then making the desired changes and saving them.
Uninstall/reinstall apps: Apps that are not used should be removed from a device to free up resources (such as those apps updating even though they are not used). Occasionally, an app may need to be reinstalled to correct problems with its configuration.
Force stop: When an app is unresponsive, you can do a force stop to close it. With iOS, press the Home button twice quickly and small previews of your recently used apps will appear. Swipe left to find the app that you want to close, and then swipe up on the app’s preview to close it using a force stop.
This list constitutes the “tools” with which CompTIA wants you to be familiar for the common mobile OS and application issues section of the exam.
Troubleshooting Mobile Security Issues
While the preceding section — and its corresponding objectives — looked at mobile devices and focused on common OS and application issues, this one builds on that and focuses on security-related issues. Once again, it looks at common symptoms and tools, differing only in that there is more of a focus on security. It needs to be pointed out, though, that CompTIA is stretching the definition of the word security to include more than many would: a fair number of the issues that appear in this section would easily have fit in the last section.
Common symptoms of problems with mobile OS and applications security issues include:
Signal drop/weak signal: Weak signals are a common culprit behind dropped signals. Before engaging in communication, signal strength on the device should be evaluated. If the signal is low (for example, no bars), then change location (step outside, drive out of the tunnel, exit the elevator, and so forth) and try for a better signal. A low battery can affect signal strength, so keep the battery charged as much as possible.
Power drain: While apps, usage, and so on can contribute to power drain, one of the biggest offenders is the search for a signal. If the antenna is not able to perform at its peak, it can reduce its efficiency and cause it to search more for a signal. Make sure that nothing is impeding the performance of the antenna.
Slow data speeds: Slow data speeds can be caused by too much interference. Try changing the channel on Wi-Fi routers to less-used channels, and performance should increase.
Unintended Wi-Fi connection: When autoconnect is enabled on devices, it is possible for them to seek out open Wi-Fi networks and try to connect to them automatically. This setting should be disabled for all devices, as an untrusted connection is a possible place for a DNS or man-in-the-middle attack to occur.
Unintended Bluetooth pairing: When anonymous devices are allowed to connect to Bluetooth-enabled devices, this is known as unintended Bluetooth pairing and it represents a security threat. Mobile security policies should be created and enforced that prevent this from occurring.
Leaked personal files/data: When authorized users access devices through unintended connections or unauthorized users get their hands on absconded devices, they can access data on the device(s) that they were never intended to see. Every firm should have a policy for protecting data (encryption) and dealing with leaks when they occur.
Data transmission overlimit: Going over the limits on data plans can be symptomatic of a hacked account. Closely monitor account usage.
Unauthorized account access: Unauthorized account access can give users access to personal files and data to which they should not have access. Closely monitor account usage.
Unauthorized root access: Security holes in mobile device operating systems can leave backdoors through which users can get unauthorized root access. The majority of these holes are closed as soon as they are discovered by patches and upgrades, so be sure to keep operating systems current.
Unauthorized location tracking: While location-based data can be very valuable when you are using maps and trying to find sites, it can also give away sensitive information if accessed by someone who should not have it. You can optimize your battery life and protect yourself by turning off Location Services. On an iPhone, turn off in Settings > Privacy > Location Services. There you will see each app listed along with its permission setting. Apps that recently used location services have an indicator next to the on/off switch, and you can configure them accordingly.
Unauthorized camera/microphone activation: The camera and microphone can be activated remotely and allow a troublemaker to spy on you. It is suggested that, when not in authorized use, you cover the camera and microphone to keep them from providing any data if remotely accessed.
High resource utilization: High resource utilization can be a tell-tell sign that a device is running more than you think it should be—perhaps the drives are being searched, the camera is recording your every move, and so forth. Monitor for high resource usage and, if discovered, find out what is causing it and respond appropriately.
There are a number of tools — really just approaches or techniques — that can be used to approach these common problems. Some of them were discussed above and are not in the list below (Factory reset/Clean install, Uninstall/reinstall apps, and Force stop). Those that remain include:
Antimalware: Keep malware definitions current and run scanning programs on every device.
App scanner: Similar to antimalware, an app scanner looks for problems with apps. On an Android phone, for example, the Lookout app automatically scans every app that you install, performs a full scan of all of the apps on your device every week, and downloads the latest definitions regularly.
Wi-Fi analyzer: This is a tool that can show you the Wi-Fi channels, and it can be useful in problem detection.
Cell tower analyzer: What the Wi-Fi analyzer can do for Wi-Fi, the Cell tower analyzer can do for cell towers—showing a graphical representation of traffic and signals.
Backup/restore: Because problems tend to happen no matter how careful one may be, it is important to back up devices and be able to restore from those backups after an incident. Some services exist beyond just giving you a place to store backups. In the Apple world, there is iTunes/iCloud/Apple Configurator. The latter simplifies mass configuration and deployment on iPhone, iPad, and iPod, and it is intended for use by schools, businesses, and institutions. In the Google world, there is Google Sync, which allows you to sync your phone, desktop, and tablet devices. Lastly, in the Microsoft world, there is OneDrive, which has been discussed previously.
As with so many issues involving troubleshooting, commonsense is most important. Using logic and a systematic approach, you can often identify and correct small problems before they become large ones.
In addition to the A+ certification, there is also CompTIA Mobility+, and the topics here are a subset of what you will find there. The exam for it covers mobile device management, troubleshooting, security, and network infrastructure.