Other Operating Systems And Technologies

D. Nearly all mobile operating systems now come with a virtual assistant. Cortana is the name of the Windows Phone (and Windows 10) virtual assistant. Windy is not currently the name of one. iOS uses Siri, and Amazon devices use Alexa.

C. DHCP servers provide TCP/IP configuration information to client computers. Clients will broadcast, searching for the DHCP server. The server will respond and provide the client with its IP address, subnet mask, default gateway, and other information. DHCP uses UDP ports 67 and 68.

A. The dd (data definition) command is used to copy files and can also be used to convert files from one format to another. It can also be used to copy blocks of data from a file and to back up the boot sector of the hard drive. The cp command will copy files but is not used for file conversion.

B. The International Mobile Subscriber Identity (IMSI) is a unique 15-digit identifier that describes a specific mobile user and their network. It's composed of three elements: a mobile country code, a mobile network code, and a mobile station identifier. The International Mobile Equipment Identity (IMEI) is also a 15-digit serial number, but it identifies the specific phone.

B. Let's say that your company needs extra network capacity, including processing power, storage, and networking services (such as firewalls), but doesn't have the money to buy more network hardware. Instead, you can purchase Infrastructure as a Service (IaaS), which is a lot like paying for utilities—you pay for what you use. Of the three, IaaS requires the most network management expertise from the client side. In an IaaS setup, the client provides and manages the software.

B. DNS has one function on the network, and that is to resolve hostnames to IP addresses. For a computer or phone to open a website, it needs to know the IP address of that website. Each DNS server has a database, called a zone file, which maintains records of hostname to IP address mappings.

A, B. Legacy means that the system is old and hopelessly outdated by today's computing standards. Legacy systems are usually defined as those using old technology in one or more of the following areas: hardware, software (applications or OS), or network protocols.

C. Platform as a Service (PaaS) adds a layer to IaaS that includes software development tools such as runtime environments. Because of this, it can be helpful to software developers; the vendor manages the various hardware platforms. This frees up the software developer to focus on building their application and scaling it. The best PaaS solutions allow for the client to export their developed programs and run them in an environment other than where they were developed.

D. To use an analogy, Finder is to macOS what Windows Explorer is to Windows 7. It lets you browse through folders and find files, disks, apps, and so on. You can change the view to see the entries with images, a list view, a column view, and so on.

A. A virtual private network (VPN) is a secured network connection made over an unsecure network. For example, if you wanted to connect your phone to your corporate network over the Internet in order to read email but you also wanted to secure the connection, you could use a VPN. IMEI and IMSI are identifier numbers, and PRI and PRL are configuration lists the phone uses.

B. In most cases, clients can get more resources instantly (or at least quickly or on-demand), which is called rapid elasticity. For the client, this is a great feature because |they can scale up without needing to purchase, install, and configure new hardware.

A. The su command (switch user, substitute user, or super user) is used to start another shell on a Linux computer. Without specifying the username, it's assumed you are trying to start a shell with superuser (or root) authority.

D. The highest of the three levels of cloud service is Software as a Service (SaaS), which handles the task of managing software and its deployment, and it includes the platform and infrastructure as well. This is the model used by Google Docs, Microsoft Office 365, and even storage solutions such as Dropbox.

D. The shell is the interpreter between the user and operating system. The most popular shell for Linux today is Bash (an acronym for Bourne Again Shell), but csh (C-shell), ksh (Korn shell), and a number of others are also in use. The terminal is used to enter commands and interface with the shell.

A. An authentication server is a device that examines the credentials of anyone trying to access the network, and it determines whether network access is granted. Said another way, they are gatekeepers and critical components to network security. A common term that you will hear in the Microsoft world is domain controller, which is a centralized authentication server.

C. A proxy server makes requests for resources on behalf of a client. Proxy servers are known for three things. One, the proxy server can cache the information requested, speeding up subsequent searches. Two, the proxy can act as a filter, blocking content from prohibited websites. Three, the proxy server can modify the requester's information when passing it to the destination, blocking the sender's identity and acting as a measure of security; the user can be made anonymous.

D. Whenever you visit a web page, you are making a connection from your device (the client) to a web server. To be more specific, a connection is requested by your Internet software (generally a web browser) using the Hypertext Transfer Protocol (HTTP) of the TCP/IP protocol suite. Your client needs to know the IP address of the web server, and it will make the request on port 80. Secure web connections are made using Hypertext Transfer Protocol Secure (HTTPS) and port 443.

B. The df (disk filesystem) command is used to show free and used disk space on a volume.

C. DNS has one function on the network, and that is to resolve hostnames to IP addresses. For a computer or phone to open a website, it needs to know the IP address of that website. The URL www.google.com means nothing to it. When a user enters the URL, the computer needs to figure out what the address is. The DNS server provides the answer, "That is 72.14.205.104." Now that the computer knows the address of the website that the user wants, it's able to go find it.

B. A Type 2 hypervisor sits on top of an existing operating system, called the host OS. This is most commonly used in client-side virtualization, where multiple OSs are managed on the client machine as opposed to on a server. The hypervisor is also called a virtual machine manager (VMM).

C. Most mobile phones have three operating systems. The first is the primary OS, such as iOS or Android. Second, there is the baseband OS that manages all wireless communication, which is actually handled by a separate processor. Third, a subscriber identity module (SIM) OS manages all data transfers between the phone and the SIM chip, which is a small memory chip that stores user account information, phone identification, and security data, and it is generally tied to a specific carrier. Some people will call the wireless communications chips in a mobile phone the radio or the modem. Consequently, you might hear about radio firmware, a radio firmware update, or a modem update. The last two terms are interchangeable with baseband update, which simply means an update of the baseband OS.

A. Mac OS X Yosemite has the ability to create a recovery disk using the Recovery Disk Assistant. This can be used to boot the system in the event of a hard drive problem and to attempt to recover the hard drive.

A. The chown (change owner) command is used to change ownership of files in Linux.

A. Updates to macOS Yosemite can be found at the App Store. Open it, and click Updates in the toolbar to see which updates are available. There will be an Install button to begin the installation. In System Preferences, there is generally a Software Update icon to help with updates as well.

B, C. The ifconfig command is used to view and change network settings, whereas iwconfig is used to view and change wireless network settings. The ipconfig command is used in Windows.

A, D. There are two ways to sync an iPhone: using Wi-Fi and using a USB connection. If you are going to use Wi-Fi, it must first be enabled in iTunes. The device should not be plugged into a USB port because that will take precedence over the Wi- Fi connection. Both devices must be on the same network SSID.

A. If presented with a scenario for installing multiple operating systems on a computer running client-side virtualization, just add the minimum hardware requirements (or recommendations) together. Treat it as if each OS needs its own minimum (which it does) and they are just sharing the available physical hardware (which they are). Also, each OS needs its own virtual network card to participate on the network and needs its security to be individually configured based on OS requirements and user needs. Treat it as though it is a separate computer.

B. Email is critical for communication, and mail servers are responsible for sending, receiving, and managing email. There are three primary email protocols used today: SMTP (port 25), POP3 (port 110), and IMAP4 (port 143).

B. In Linux, the mv (move) command is used to rename files. The cp command copies a file, but that is a different process than moving it. rm is short for remove, and it deletes files. ren is a DOS or Windows command to rename files.

C. Apple produces iOS, and all of its apps can be found on the App Store. Google Play is used for Android-based devices, and it replaced Android Market. Windows Phone apps are found at the Windows Store.

B. The grep command (short for the impossibly long "globally search a regular expression and print") does just what it says it does: it searches for a string of text and then displays the results of what it found.

C. It's a fairly common myth that there are no macOS viruses out there. The reality is that every operating system can be affected by malware. Because of this, it is imperative to have protection on every machine. Additionally, this protection—in the form of definition files—must be kept current and up-todate. The best way to do that is to set the software to automatically update.

A. The objectives might say Remote Disk, but the feature is officially called Remote Disc (disc with a c). This feature lets you access files on a CD or DVD installed in one machine on a remote machine. This is handy if you need to retrieve files from a disc and the workstation at which you are sitting does not have a built-in drive.

A. The traditional type of cloud that usually comes to mind is a public cloud, like the ones operated by third-party companies such as Microsoft, Google, HP, Apple, Netflix, and Amazon. These clouds offer the best in scalability, reliability, flexibility, geographical independence, and cost effectiveness. Whatever the client wants, the client gets. For example, if the client needs more resources, it simply scales up and uses more.

B. The search feature within macOS is Spotlight, and a magnifying glass icon in the upper-right corner of the menu bar represents it (or you can press Command+spacebar from any app). Spotlight can search for documents, images, apps, and so on.

B. As great as macOS is, there are times when you need Windows—for compatibility purposes with apps, legacy data, and many others. Because of this, you can use Boot Camp to install Windows on a Mac computer and then choose between operating systems as you boot. The Mac computer must be Intel based, you need to have a 64-bit version of Windows, and you need a minimum of 30GB of free disk space for it to work.

D. The ls (list) command is used in Linux to show the contents of a directory.

B. SMTP uses port 25, and IMAP4 uses port 143. However, when they run over SSL, SMTP uses port 465, and IMAP4 uses port 993. SMTP over TLS uses port 587, and POP3 over SSL or TLS uses port 995.

D. The chmod (change mode) command is used in Linux to change file permissions.

A. The Preferred Roaming List (PRL) is the reference guide the phone uses to connect to the proper cell phone tower when roaming. Product Release Instruction (PRI) contains settings for configuration items on the device that are specific to the network that it's on. Both PRI updates and PRL updates normally happen when the primary OS on the phone is updated, but your carrier may let you update them manually.

A. The fsck (file system check) command is used to examine volumes for errors, as well as attempt to fix them. The command is analogous to the chkdsk command for Windows-based computers. Be sure that the volume is unmounted before using fsck, to avoid corrupting data.

A. An Intrusion Protection System (IPS) is an active device. It monitors network traffic, and when it detects an anomaly, it can take actions to attempt to stop the attack. For example, if it senses suspicious inbound traffic on a specific IP port, it can shut the port down, block the sender, or reset the TCP connection.

B. Android started off as its own company and was purchased by Google in 2005. Like Google's Chrome OS, Android is Linux based. It's primarily installed on smartphones, but it is also found on specialized television, automobile, and wristwatch devices. Versions of Android are named after candy, such as Ice Cream Sandwich, Jelly Bean, KitKat, and Lollipop.

D. Macs use the HFS+ file system, which Apple states does not require defragmentation like FAT or NTFS do. Therefore, disk defragmentation is not generally necessary. Regardless of the operating system, you should always back up data (unless you don't mind losing it), install and update antivirus software, and keep drivers and firmware current.

B. File servers provide a central repository for users to store, manage, and access files on the network. Networks can also use network attached storage (NAS) devices, which are stand-alone units that contain hard drives, come with their own file management software, and connect directly to the network. If a company has extravagant data storage needs, it can implement a storage area network (SAN). A SAN is basically a network segment, or collection of servers, that exists solely to store and manage data.

A. One of the best ways always to have the latest version of files, regardless of the device that you are using to access them, is to have them stored/accessed remotely. iCloud is Apple's answer to remote storage, and you can configure your Apple devices to place files there automatically, or use it for backup.

D. The ps (process status) command in Linux is used to show currently running processes.

C. On a Mac, it's possible to run a large number of things at one time, whether those things in question are apps or desktops. Apple's Mission Control is an easy way to see what is open and switch between applications. To access Mission Control, you can press the Mission Control key on an Apple keyboard, click the Mission Control icon in Dock (or Launchpad), or swipe up with three or four fingers on a trackpad.

A. Passwords are not synchronized between devices. Types of data that are synchronized include contacts, programs, email, pictures, music, videos, calendar, bookmarks, documents, location data, social media data, and ebooks.

D. The goal of unified threat management (UTM) is to centralize security management, allowing administrators to manage all of their security-related hardware and software through a single device or interface. A UTM device can generally provide the following types of services: packet filtering and inspection, intrusion protection service, gateway anti-malware, spam blocking, malicious website blocking, and application control.

C. The major feature of virtualization is breaking down that one-to-one hardware and software barrier. The visualized version of a computer is appropriately called a virtual machine (VM). Thanks to VMs, it is becoming far less common to need dual-boot machines today than in the past. VMs allow computers to do things like run five instances of an OS or one instance of several different OSs.

B. When an app hangs inside the Mac OS, you can use Force Quit to force it to close. Most devices, whether running Mac OS or iOS, offer similar options. You get to Force Quit by looking at the Apple menu or by pressing Command+Option+Esc, which is analogous to pressing Ctrl+Alt+Del on a PC.

B. Companies can purchase virtualization software to set up individual clouds within their own network. That type of setup is referred to as a private cloud. Running a private cloud pretty much eliminates many of the features that companies want from the cloud, such as rapid scalability, and eliminates the need to purchase and manage computer assets. The big advantage, though, is that it allows the company to control its own security within the cloud.

A. Some mobile devices give you the option to improve the ability of the computer to recognize how you personally actuate the sensors. For example, many phones allow you to re-calibrate (or retrain) the onscreen touch keyboard. That would be the first thing to try in this situation.

C. The International Mobile Equipment Identity (IMEI) is a 15-digit serial number that is unique to each phone. If a phone is reported stolen, the IMEI will be declared invalid. The IMEI can be displayed on most phones by dialing *#06#. AT&T and T-Mobile were the first networks to use IMEI. The International Mobile Subscriber Identity (IMSI) is also a unique 15-digit identifier, but it describes a specific mobile user and their network.

D. The passwd command is used in Linux to change user passwords. The similar-looking pwd command displays the current directory.

B. The backup software for all current versions of Mac OS is called Time Machine. It allows users to back up and restore files just like any other commercial backup software.

D. Google offers the Android operating system to the mobile community under an open source license. Apple and Microsoft keep their mobile OSs closed source, and they manage all the development and marketing of their operating systems. BlackBerry OS was closed source as well. Apps for mobile operating systems are created using a free software development kit (SDK). Android apps are installed using an Android application package (APK).

C. The du (disk usage) command will show how much disk space is being used. By default, it shows usage in disk blocks, which isn't very reader-friendly. Use the -h option to show it in kilobytes, megabytes, and so on, and the -a option to show all files and directories. To use both together, the syntax would be du -ah /[volume_name].

C. The vi command (shortened from visual) is used to open a window-oriented text editor in Linux. The cd command is for change directory, ps lists processes, and cp is copy.

C. If each client has been promised 16GB RAM, then the server must have enough RAM to give each client their allotment. This means 64GB in this case. The assumption is that the hypervisor will require no RAM on its own. In reality, it probably will require a little but not much.

B. Depending on the variant of Linux you are running, apt (Advanced Package Tool) can be useful in getting the patches from a repository site and downloading them for installation. The most common command used with this tool is apt-get, which, as the name implies, gets the package for installation.

A. When configuring a mobile email client to access a commercial email provider, you typically just need your username and password to establish connectivity. Examples include Google, Yahoo, Outlook.com, and iCloud.

C, D. To interact with a mobile operating system, people can use gesture-based interaction, or gestures. Mobile devices also have emergency notifications built-in, for Amber alerts or government-declared emergencies. Software development kits (SDKs) are available for nearly all OSs, as are power options.

D. Screen sharing is a macOS feature that allows you to share your screen with others. It requires a Virtual Network Computing (VNC) connection.