Lesson 15: Networking Concepts

What type of address identifies a network interface in the context of the local network segment only? A. A Media Access Control (MAC) address B. IP address C. DNS D. URL

A. A Media Access Control (MAC) address Each host, or device, is identified by the address of its network interface by the MAC address, which is assigned to the network adapter at the factory. The IP address is used to identify each device on a given network using a 32-bit or 64-bit binary value. The Domain Name System (DNS) is a method of mapping people-friendly names to devices on a network. The Uniform Resource Locator (URL) is a web address that contains all information needed by a browser to locate an item, like a web page or a file, on the web rather than a device.

What is a Wide Area Network (WAN)? A. A network that connects sites in different geographic locations B. A network in a single location C. A company that specializes in providing Internet access D. A company that operates the national telephone networks

A. A network that connects sites in different geographic locations A Wide Area Network (WAN) connects sites in different geographic locations. WANs usually make use of telecommunications and service provider networks rather than being directly operated by the network administrators. A network that is only in a single location is called a Local Area Network (LAN). A LAN is typically owned and operated by the company or organization that uses it. A company that specializes in providing Internet access is called an Internet Service Provider (ISP). A company that operates the national telephone networks is called a telecommunications company, or telco for short.

What is the difference between HTTP and HTTPS protocols? A. HTTPS serves SSL (Secure Sockets Layer) secured HTML web pages, whereas HTTP serves unsecured web pages. B. HTTP serves web pages on the extranet, whereas HTTPS serves web pages on the intranet. C. HTTP does not require DNS to resolve a web address to an IP address, whereas HTTPS does. D. HTTP can serve HTML web pages, whereas HTTPS can serve HTML web pages, as well as XML pages displayed as HTML.

A. HTTPS serves SSL (Secure Sockets Layer) secured HTML web pages, whereas HTTP serves unsecured web pages. Hypertext Transfer Protocol (HTTP) enables web browsers to request resources from an HTTP server. Once a server is protected with an SSL certificate, HTTPS is required to serve web pages from that server. Both HTTP and HTTPS can be used to serve pages on the intranet and extranet, depending on which servers have SSL certificates applied. Whether using the HTTPS or the HTTP protocol, DNS is required to resolve the web address. Browsers do not display XML files as HTML web pages when using the HTTPS or the HTTP protocol. Since XML tags are not standard HTML tags, browsers cannot interpret them.

What protocol is usually used to provide logical addressing on networks? A. Address Resolution Protocol (ARP) B. Internet Protocol (IP) C. Internet Control Message Protocol (ICMP) D. Transmission Control Protocol (TCP)

B. Internet Protocol (IP) Internet Protocol (IP), part of the Internet Layer, is the main protocol in the TCP/IP suite. It is responsible for logical addressing and the routing of packets between hosts and networks. Address Resolution Protocol is used to resolve a host's local Media Access Control (MAC) address to a logical IP address. Internet Control Message Protocol (ICMP) is responsible for sending messages and reports on errors regarding the delivery of packets. Transmission Control Protocol (TCP) is part of the transport layer, which provides communication sessions between computers.

What are the key features of a packet switching network? A. A packet sent down the network can switch its destination mid-stream. B. Nodes within the network can perform a forwarding function, allowing a packet to utilize any available path through the network. C. Packets can be switched from a TCP/IP protocol to another available protocol to increase the transmission speed. D. A packet switching network opens a direct channel on which to transmit the packet, so a break in the channel stops the transmission.

B. Nodes within the network can perform a forwarding function, allowing a packet to utilize any available path through the network. Packet switching makes the network robust against link failures. It is beneficial for the network to use small packets that are easy to re-send. Packets include a header with a destination address. Delivery to that address is a requirement, rather than an option. Packet switching is a networking feature used with the TCP/IP protocol. Packet switching is an improvement over the older method of transmitting packets over a direct channel, or circuit. In the old system, when the circuit breaks, the communication is stopped; whereas, packet switching attempts to find other pathways to ensure that the transmission occurs correctly.

What is a packet made up of? A. A packet is the destination address of a unit of data being transmitted over the network. B. A packet is the data inside the wrapper used for each data unit transmitted over the network. C. A packet consists of a number of fields contained within a header section plus a payload. D. A packet consists of a payload wrapped around a header section.

C. A packet consists of a number of fields contained within a header section plus a payload. Packets are used to transmit data over networks. The structure of a packet includes a header which provides information such as: the protocol type, source address, destination address, and error correction. It is followed by the data to be transmitted. The packet is the wrapper, which contains the header, with its protocol and address information, and the payload. The packet's destination is one of the items of data included in the header. The payload, located inside the packet along with the header, is the data being transmitted over the network.

What type of device is used to transfer packets between different networks? A. A hub B. A switch C. A router D. A Network Interface Card (NIC)

C. A router Routers are devices that connect to the network to act in a manner similar to a traffic officer directing traffic. They are responsible for the forwarding function used in packet switching. A Small Office Home Office (SOHO) network switch is a device used to connect 4 or 8 computers together in an Ethernet LAN. A hub is a device often used to connect a variety of devices to the network. In a home automation system, the thermostat, security system and clock may all be plugged into a hub. The Network Interface Card (NIC) on a computer allows it to connect to the network.

Which of the following parts of a friendly URL is dependent on a name resolution service? A. File path B. Protocol type C. Top level domain D. IP address

C. Top level domain A Top-Level Domain (TLD) defines a broad class domain for a web-based URL. For example, a "dot com" (.com) address is a popular TLD that specifies entities that use this naming scheme. The protocol type provided in the web address describes the access method or service type being used. For example, HTTP:// denotes the Hypertext Transfer Protocol. The file path portion of the web address specifies the directory and file name location of the resource on the designated host. The IP address is the result of the DNS resolution of the host location from the web address. People prefer web addresses, while networks need IP addresses.

Which email protocol(s) are used to download messages from a mail server? A. Either Internet Message Access Protocol (IMAP) or Simple Mail Transfer Protocol (SMTP) B. Either Post Office Protocol (POP) or Mail Exchanger (MX) C. Either Mail Exchanger (MX) or Internet Message Access Protocol (IMAP) D. Either Post Office Protocol (POP) or Internet Message Access Protocol (IMAP)

D. Either Post Office Protocol (POP) or Internet Message Access Protocol (IMAP) An email recipient, using his or her mail client software, can connect with the mailbox on the server and download the message using either Post Office Protocol (POP) or Internet Message Access Protocol (IMAP). Mail Exchanger (MX) is the DNS record that lists the IP address for the recipient's email address, and is used when DNS resolves that address. MX records are used to determine your email's delivery route. If multiple mail servers are used they can be ranked by priority. Once a message is in the queue on the Exchange server, it's the Simple Mail Transfer Protocol (SMTP) session that contacts DNS to obtain the IP address.

Which protocol allows people to use names/labels, rather than numeric addresses, to address network resources? A. URL B. IP address C. MAC address D. Domain Name System (DNS)

D. Domain Name System (DNS) The Domain Name System (DNS) is a method of assigning names or people-friendly words to devices on a network. An example would be: comptia.org. The IP address is used to identify each device on a given network using a 32-bit binary value expressed as four decimal numbers separated by periods (for IP version 4). Each host, or device, is identified by the address of its network interface by the MAC address, which is assigned to the network adapter at the factory. The Uniform Resource Locator (URL) is a web address, not a protocol, that contains all the information needed by a browser to locate an item on the web, like a web page or a file.