CompTIA A+ Practice Tests. Docter Quentin
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Название: CompTIA A+ Practice Tests
Автор: Docter Quentin
Издательство: John Wiley & Sons Limited
Жанр: Зарубежная образовательная литература
isbn: 9781119372677
isbn:
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D. Routers operate at the Network layer (Layer 3) of the OSI model. Because of this, they make their decisions on what to do with traffic based on logical addresses, such as an IP address.
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C. A firewall is a hardware or software solution that serves as your network’s security guard. Firewalls can protect you in two ways: they protect your network resources from hackers lurking in the dark corners of the Internet, and they can simultaneously prevent computers on your network from accessing undesirable content on the Internet.
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D. The default gateway is the address to the network’s router, which will allow the host to communicate with hosts not on the local network.
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D. The Remote Desktop Protocol (RDP) allows users to connect to remote computers and run programs on them. It uses port 3389.
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A. F-connectors are threaded and screw into place. The BNC connector locks by twisting one-quarter turn. SC and ST connectors are for fiber-optic cable.
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C. A personal area network (PAN) is a small-scale network designed around one person within a limited boundary area. The term generally refers to networks that use Bluetooth technology.
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B. The connectors pictured are BNC connectors. They are identifiable by their groove-and-notch fastening mechanism that locks by twisting one-quarter turn. F-connectors are easily identifiable because they are threaded. SC and ST connectors are for fiber-optic cable.
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D. At the Internet layer of TCP/IP, Address Resolution Protocol (ARP) resolves logical IP addresses to physical MAC addresses built into network cards. Reverse ARP (RARP) resolves MAC addresses to IP addresses.
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C. The 169.254.0.0/16 range in IPv4 is the APIPA range, used for automatic configuration if the host can’t locate a DHCP server. The same task in IPv6 is accomplished with a link local address in the FE80::/10 range.
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D. The connectors are a four-pin RJ-11, typically used for telephone installations, and an eight-pin RJ-45 connector, used on UTP and STP for network transmissions.
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D. Universal Plug and Play (UPnP) is a standard designed to simplify the process of connecting devices to a network and to enable those devices to automatically announce their presence to other devices on the network.
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A, C. Addresses in the FE80::/10 range are link local unicast addresses. A link local address is assigned to each IPv6 interface but is not routable on the Internet. If this is the only address the host has, it will not be able to get on the Internet.
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C. The connector shown is a type of mini form factor (MFF) fiber-optic connector called a local connector (LC). It’s especially popular for use with Fibre-Channel adapters, fast storage area networks, and Gigabit Ethernet adapters.
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A. The File Transfer Protocol (FTP) is optimized for downloading files from servers. It uses port 21.
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D. The Lightweight Directory Access Protocol (LDAP) is a directory services protocol based on the X.500 standard. LDAP is designed to access information stored in an information directory typically known as an LDAP directory or LDAP database. This often includes employee phone numbers and email addresses.
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B. The default subnet mask for class B networks is 255.255.0.0, or written in shorthand, /16.
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D. If you’re working on a larger network installation, you might use a punchdown tool. It’s not a testing tool but one that allows you to connect (that is, punch down) the exposed ends of a wire into wiring harnesses, such as a 110 block.
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C. Fiber-optic broadband Internet offers fast speeds (often in the 1Gbps range) but is also the most expensive.
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A. The correct order for a T568B cable is white/orange, orange, white/green, blue, white/blue, green, white/brown, brown.
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A. Cable television installations typically use either RG-6 or RG-59 cable. RG-6 is slightly thicker, can run longer distances, and supports digital signals. RG-59 is suited only for analog TV signals.
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C. Server Message Block (SMB) is a protocol used to provide shared access to files, printers, and other network resources. It uses TCP ports 137–139 and 445.
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A, C. Each IPv6 interface can and often does have multiple addresses assigned to it. IPv6 is backward compatible with IPv4.
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B, C. A hub is a device used to link several computers together. Hubs are simple devices that possess no real intelligence, and they work at Layer 1 of the OSI model. Extenders simply allow a signal to propagate for a longer distance, and they also work at Layer 1. Switches are Layer 2 devices, and routers work at Layer 3.
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D. RG-6 and RG-59 can, in many cases, be used interchangeably. RG-6 is a better choice because it supports digital signals and has a longer range (304 meters or 1,000 feet). RG-59 can run up to 228 meters (750 feet). Both have impedance of 75 ohms, and both use BNC connectors or F-connectors.
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A, D. Multimode fiber and UTP CAT6 and newer support 10Gbps transmission speeds.
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B. The Apple Filing Protocol (AFP) was developed by Apple as a file transfer protocol similar to FTP and Server Message Block (SMB). It was the default file transfer protocol on Mac OS until Apple changed to SMB2 in 2013.
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B. 127.0.0.7 is the loopback address, used to ping the local network interface. The IPv6 equivalent is ::1.
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B. Port triggering allows traffic to enter the network on a specific port after a computer makes an outbound request on that specific port. For example, if a computer on your internal network makes an outbound Telnet request (port 23), subsequent inbound traffic destined for the originating computer on port 23 would be allowed through.
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D. If you need to trace a wire in a wall from one location to another, a tone generator and probe is the right tool to use. It consists of two pieces: a tone generator and a probe. To use it, attach one end to one end of the cable, such as the end at the computer. Then go to the patch panel with the other end of the probe to locate the cable. These are lifesavers when the cables are not properly labeled.
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B. Dynamic Host Configuration Protocol (DHCP) dynamically assigns IP addresses and other IP configuration information to network clients.
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D. Shielded twisted pair (STP) cabling has a foil shield surrounding the wire pairs to decrease electrical interference. Some STP cables also shield individual wire pairs. Unshielded twisted pair (UTP) does not have the shielding. Both types use RJ-45 connectors, can follow the T568A wiring standard, and can be produced as plenum-rated cable that does not produce poisonous gas when burned.
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D. The connectors shown are ST connectors, which are used with fiber-optic cable. ST connectors are the most popular fiber connector, and they attach with a BNC-like locking mechanism.
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B. Switches work at Layer 2 as do bridges, and they provide centralized connectivity just like hubs. Switches examine the Layer 2 header of the incoming packet and forward it properly to the right port and only that port. Switches are multiport bridges.
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B. Email is pushed from clients to servers using the Simple Mail Transfer Protocol (SMTP). SMTP uses port 25.
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C. Of the Wi-Fi standards, 802.11n has the longest range by default, at roughly 70 meters indoors and 250 meters outdoors. 802.11ac is newer and faster than 802.11n, but it transmits exclusively in the 5GHz range, which restricts its functional distance.
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C. Multimeters are versatile electronic measuring tools. A multimeter can measure voltage, current, and resistance on a wire.
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A. Simple Network СКАЧАТЬ