CompTIA A+ Practice Tests. Docter Quentin

multiple computers using UTP, use a hub or a switch.

174

A. Cable testers are indispensable tools for any network technician. Usually you would use a cable tester before you install a cable to make sure it works. Of course, you can test them after they’ve been run as well.

175

C. Internet Message Access Protocol (IMAP) is a secure protocol designed to download email. It has several advantages over the older Post Office Protocol 3 (POP3). First, IMAP4 works in connected and disconnected modes. Second, it lets you store the email on the server, as opposed to POP3, which requires you to download it. Third, IMAP4 allows multiple clients to be simultaneously connected to the same inbox.

176

A. The Domain Name System (DNS) server is responsible for resolving host names, such as www.google.com, to IP addresses to enable communication. If it’s not working properly or you can’t connect to it, you won’t be able to browse the Internet using friendly website names.

177

C. Single-mode fiber (SMF) can provide data throughput rates of 10Gbps at a distance of 40 kilometers.

178

B. RG-59 network cable can run for about 228 meters (750 feet). The slightly thicker RG-6 can run for about 304 meters (1,000 feet).

179

B. Secure Shell (SSH) can be used to set up a secure Telnet session for remote logins or for remotely executing programs and transferring files. Because it’s secure, it was originally designed to be a replacement for the unsecure telnet command.

180

B, C. Switches and bridges work at Layer 2. Switches are multiport bridges.

181

B. Computers are able to differentiate where the network ID ends and the host address begins through the use of a subnet mask.

182

B. Transmission Control Protocol (TCP) guarantees packet delivery through the use of a virtual circuit and data acknowledgments, and User Datagram Protocol (UDP) does not. Because of this, TCP is often referred to as connection oriented, whereas UDP is connectionless.

183

D. Telnet lets users log into another machine and “see” the remote computer in a window on their screen. Although this vision is text only, the user can manage files on that remote machine just as if they were logged in locally.

184

C. A CIDR shorthand notation of /26 corresponds to the subnet mask 255.255.255.192.

185

C. 802.11g specifies a maximum of 54Mbps transmissions in the 2.4GHz frequency range.

186

C. Server Message Block (SMB) is a protocol used to provide shared access to files, printers, and other network resources. In a way, it functions a bit like FTP only with a few more options, such as the ability to connect to printers, and more management commands.

187

C. Telnet lets users log into another machine and “see” the remote computer in a window on their screen. Although this vision is text only, the user can manage files on that remote machine just as if they were logged in locally. Telnet uses port 23.

188

D. A wireless locator or a Wi-Fi analyzer can be either a handheld hardware device or specialized software that is installed on a laptop and whose purpose is to detect and analyze Wi-Fi signals. It can detect where signals are strong or weak to determine whether there are potential security issues.

189

C. Internet traffic is not encrypted by default. Websites that are secure and encrypt their transmissions will start with HTTPS://rather than HTTP://. These sites can be trusted to encrypt the data, and their identity is verified.

190

A. The main Internet layer protocol is Internet Protocol (IP), and it’s the workhorse of TCP/IP. Another key protocol at this layer is Internet Control Message Protocol (ICMP), which is responsible for delivering error messages. If you’re familiar with the ping utility, you’ll know that it utilizes ICMP to send and receive packets.

191

C. There are three types of addresses in IPv6: unicast, anycast, and multicast. A unicast address identifies a single node on the network. An anycast address refers to one that has been assigned to multiple nodes. A multicast address is one used by multiple hosts.

192

A. Of the wireless encryption methods listed, WPA2 is the newest and most secure. Some routers offer WPA2 Enterprise, which is a great choice as well.

193

B. A wide area network (WAN) covers large geographical areas and often supports thousands of users.

194

A. Developed by Microsoft, the Remote Desktop Protocol (RDP) allows users to connect to remote computers and run programs on them. When you use RDP, you see the desktop of the computer you’ve signed into on your screen. It’s like you’re really there, even though you’re not.

195

B. Secure Shell (SSH) can be used to set up a secure Telnet session for remote logins or for remotely executing programs and transferring files. SSH uses port 22.

196

A. Private IP addresses are not routable on the Internet. The private IP address range for class A networks is 10.0.0.0/8.

197

D. One of the key features of routers is that they break up broadcast domains. Broadcast traffic on one side of the router will not get passed to the other side, which greatly reduces network traffic.

198

C. A loopback plug is for testing the ability of a network adapter to send and receive. The plug gets plugged into the NIC, and then a loopback test is performed using troubleshooting software. You can then tell whether the card is working properly.

199

D. UTP cables are limited to 100 meters, so CAT5 and CAT7 will not work. You need fiber, and multimode fiber (MMF) can span distances of 300 meters.

200

C, D. Simple Mail Transfer Protocol (SMTP, port 25), Post Office Protocol 3 (POP3, port 110), and Internet Message Access Protocol (IMAP, port 143) are all email protocols. SMTP is for sending email. POP3 and IMAP are for downloading email.

201

A. Fiber-optic cabling uses pulses of light instead of electric voltages to transmit data, so it is immune to electrical interference and to wiretapping.

202

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.

203

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.

204

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.

205

D. The Remote Desktop Protocol (RDP) allows users to connect to remote computers and run programs on them. It uses port 3389.

206

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.

207

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.

208

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.

209

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.