Exam 1 Q's

The hexidecimal number 4A01 when converted to binary is: a.) 010010100000000 b.) 0100101000010001 c.) 0100101000000001 d.) 0100101010000001

0100101000000001 *Reason: Convert (4A01) to binary: (4) = (0100) (A) = (1010) (0) = (0000) (1) = (0001) So (4A01) = (0100101000000001)

Select a valid IPV6 address a.) 198.51.10.1 b.) 2001:db8:1f70:999:de8:7648:3a49:6e8 c.) 198.51.100.215 d.) 2001:db8:1f70:999:7648:3a49:6e8

2001:db8:1f70:999:de8:7648:3a49:6e8 *Reason: The IPv6 address notation is eight groups of four hexadecimal digits with the groups separated by colons, for example 2001:db8:1f70:999:de8:7648:3a49:6e8, although there are methods to abbreviate this notation. For comparison, the IPv4 notation is four groups of decimal digits with the groups separated by dots, for example 198.51.100.1.

HTTPS uses port number a.) 80 b.) 21 c.) 143 d.) 443

443

Internet Message Access Protocol (IMAP) or Post Office Protocol (POP) are protocols used by a client to send messages from a mail server. [T/F]

False

The application layer is the seventh layer of the Internet model and specifies the type of connection and the electrical signals that pass through it. [T/F]

False

Using HTTP version 1.0 a keep-alive: tells the server "please keep this connection open, I'll request more" [T/F]

False

What do the twists in twisted pair cabling do to improve network communications? a.) Reduces a specific type of interference, called EMI. b.) Resistant to interference and corrosion c.) Data can travel longer distances d.) Data will travel faster

Reduces a specific type of interference, called EMI. *Reason: These are the cables that are used most frequently for Ethernet purposes. They are called "twisted pair" because there are pairs of wires in the cable that are twisted together. This is done to prevent electromagnetic interference from outside sources and other wire pairs in proximity.

The fourth layer of the OSI model is called the __________ layer. a.) Network b.) Transport c.) Session d.) Data Link e.) Presentation

Transport

Star-Ring topology is most commonly used to implement wireless networks? [T/F]

False *Reason: Hide Feedback Wireless mesh networks are increasingly being used since it is far simpler and cheaper to connect using radio signals. Wired mesh networks tend to be uncommon, mainly because connecting all nodes to all other nodes is expensive and impractical.

The DNS root servers have only one job: to delegate name resolution to other DNS servers. [T/F]

True

The data link layer accepts messages from the network layer and controls the hardware that transmits them. [T/F]

True

Network layer functions include a.) providing services for an application program b.) identifying all hosts in the network c.) dealing with transmission errors d.) regulating the flow of data

identifying all hosts in the network *Reason: Also, determining the next device to which the message should be sent to reach the final destination

The most common Error Detection Method is...... a.) Parity b.) Cyclical Redundancy Check c.) Checksums d.) Parity Check

Cyclical Redundancy Check *Reason: CRC Treats message as a single binary number (P) Divides by a preset number (the generator, G) Uses remainder as the check value (R) Generator is chosen so that remainder is the correct number of bits Most powerful and most common Detects 100% of errors (if number of errors

A URL is nothing more than the address of a given unique resource on the Web. [T/F]

True *Reason: In theory, each valid URL points to a unique resource. Such resources can be an HTML page, a CSS document, an image, etc.

_________ is the process of determining the path that a message will travel from sending computer to receiving computer. a.) Packetizing b.) Addressing c.) Routing d.) Interfacing e.) Broadcasting

Routing *Reason: When a router receives an IP packet, the router checks its routing table and compares all available paths to get the destination network of the received IP packet and selects the fastest path from all available paths. RIP, and OSPF are examples of routing protocols. The main differences between Routing and Switching is that the function of Switching is to switch data packets between devices on the same network (or same LAN - Local Area Network). The function of Routing is to Route packets between different networks (between different LANs - Local Area Networks).

A destination port number at the transport layer identifies which application on a computer should receive the data transmission. [T/F]

True

Because there is a limit on the length of a frame that the data link layer can transmit from node to node, the transport layer breaks up the message from the application layer into several smaller segments. [T/F]

True

DHCP dynamically assigns an IP address to a computer. [T/F]

True

For the requests from the Web browser to be understood by the Web server, they must use the same standard protocol or language. [T/F]

True

In the OSI model, the application layer provides a set of utilities for applications and is the end user's access to the network. [T/F]

True

A(n) _________ is a specially formatted request used to perform IP address to data link address resolution. a.) Autonomous System Request b.) Link state request c.) HTTP request d.) Address Resolution Protocol request e.) Domain Service Request

Address Resolution Protocol request *Reason: Most of the computer programs/applications use logical address (IP address) to send/receive messages, however the actual communication happens over the physical address (MAC address) i.e from layer 2 of OSI model. We need to get the destination MAC address which helps in communicating with other devices. This is where ARP translates the IP address to physical address. The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. ARP broadcasts a request packet to all the machines on the LAN and asks if any of the machines know they are using that particular IP address. When a machine recognizes the IP address as its own, it sends a reply so ARP can update the cache for future reference and proceed with the communication.

The most widely used LAN protocol is: a.) TCP-IP b.) Ethernet c.) DNS d.) DHCP

Ethernet *Reason: IEEE 802.3 standard and Ethernet II Most widely used LAN protocol, developed jointly by Digital, Intel, and Xerox, now an IEEE standard Most widely used LAN protocol Uses contention media access control

A physical circuit refers to the transmission characteristics of the connection, such as the speed at which data is being sent through the connection. [T/F]

False *Reason: A Logical circuit refers to the transmission characteristics of the connection. Physical circuit is the Cables, Wires etc.

DNS is normally responsible for translating IP address to host names. [T/F]

False *Reason: DNS translates domain names to IP addresses so browsers can load Internet resources.

Each network interface on your computer is identified by a series of letters known as a MAC address [T/F]

False *Reason: Each network interface on your computer is identified by a series of letters and numbers known as a MAC address.

IP packets provide guaranteed delivery over the network. [T/F]

False *Reason: IP packets can get lost, can be delivered out of order, and can be corrupted. There are no guarantee of delivery.

IPv6 uses 32-bit addresses as opposed to the 128-bit addresses used by IPv4 allowing for a substantially larger number of possible addresses. [T/F]

False *Reason: IPv6 uses 128-bit addresses as opposed to the 32-bit addresses used by IPv4, allowing for a substantially larger number of possible addresses. With each bit corresponding to a '0' or '1', this theoretically allows 2^128 combinations or 340 trillion, trillion, trillion addresses. By contrast, IPv4 permits 2^32 combinations for a maximum of approximately 4.7 billion addresses.

In TCP/IP, the parts of the IP address that are used as the network and host addresses are fixed, so the network and host addresses can be determined without more information. [T/F]

False *Reason: In TCP/IP, the parts of the IP address that are used as the network and host addresses are not fixed, so the network and host addresses above cannot be determined unless you have more information. This information is supplied in another 32-bit number called a subnet mask.

Polling is the process of permitting all clients to transmit or receive at any time [T/F]

False *Reason: Polling - The server (periodically) polls the client if it has data to send

TCP includes a sequence number to keep track of the total number of packets sent. [T/F]

False *Reason: TCP includes a sequence number so that the packets can be reassembled at the destination in the correct order.

The Internet's Transmission Control Protocol (TCP) uses the MTU to determine the minimum size of each packet in any transmission. [T/F]

False *Reason: The Internet's Transmission Control Protocol (TCP) uses the MTU to determine the maximum size of each packet in any transmission.

With Post Office Protocol (v3, therefore POP 3) emails remain on the mail server [T/F]

False *Reason: The key difference is where your emails are stored. With POP your emails are downloaded to your device and deleted from the server (unless you change the default settings). With IMAP, emails "reside" on the server and you can easily read and interact with emails from multiple devices.

The top-level DNS servers delegate to hundreds of thousands of other top-level DNS servers. [T/F]

False *Reason: The top-level DNS servers delegate to hundreds of thousands (maybe millions by now?) of second-level DNS servers

With contention, a computer does not have to wait before it can transmit. A computer can transmit at anytime. [T/F]

False *Reason: With Contention Access you transmit whenever a circuit is available

Digital transmission produces more errors than analog transmission. [T/F]

False *Reason: Digital transmission produces fewer errors. Easier to detect and correct errors, since transmitted data is binary (1s and 0s, only two distinct values).

In step 5 of the DHCP process, the server sends a REQUEST (or DHCPREQUEST) packet, letting the client know that it intends to use the address. [T/F]

False *Reason: The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address.

The newer form of IP, version 6 (IPv6): a.) Is running out of address space to support the growth of the Internet b.) Has a 20 byte header c.) Has an increased address size from 32 bits to 128 bits d.) Does not include version number in its header e.) Does not include hop limit in its header

Has an increased address size from 32 bits to 128 bits *Reason: IPv6 uses 128-bit addresses as opposed to the 32-bit addresses used by IPv4, allowing for a substantially larger number of possible addresses. With each bit corresponding to a '0' or '1', this theoretically allows 2^128 combinations or 340 trillion, trillion, trillion addresses. By contrast, IPv4 permits 2^32 combinations for a maximum of approximately 4.7 billion addresses.

In DHCP, how does your computer choose an IP address? a.) Sends the request to the DHCP server b.) Send the request to another host on the network c.) Broadcast the request on the network d.) Contact the router to choose one

Sends the request to the DHCP server *Reason: The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer.

Radio data transmission requires that each device has a radio receiver/transmitter and uses a specific frequency. [T/F]

True *Reason: A computer's wireless adapter translates data into a radio signal and transmits it using an antenna. A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection. The process also works in reverse, with the router receiving information from the Internet, translating it into a radio signal and sending it to the computer's wireless adapter. They transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data.

HTTP response status codes indicate whether a specific HTTP request has been successfully completed. [T/F]

True *Reason: Responses are grouped in five classes: Informational responses (100-199) Successful responses (200-299) Redirects (300-399) Client errors (400-499) Server errors (500-599)

An ARP entry is usually learned and is kept on a device for a certain ammount of time, as long as it is being continually used. [T/F]

True *Reason: Most of the time, the computer will use dynamic ARP entries. This means that the ARP entry (the Ethernet MAC to IP address link) has been learned (usually from the default gateway) and is kept on a device for a given period of time, as long as it is being used.

With Client-Based Architecture, application software on the client computers contains presentation, application, and data access logic [T/F]

True *Reason: Server (host) simply stores the data Most common in the 1980s

What is the most common type of cabling used in networks? a.) Multimode fiber b.) Fiber Optic c.) Twisted pairs d.) Coaxial

Twisted pairs *Reason: There are two main classifications of twisted pair cables: The first one is Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP). STPs have an extra layer of shielding to make them more resistant to outside interference, and, thus, have an improved ability to maximize bandwidth in comparison to UTPs. The drawback to this is that they are far heavier and cost more, which is why their primary use is within high-end applications where prevention of interference is a top priority.

In NDP Neighbor Solicitation does the following task; a.)advertise their presence together with various link and Internet parameters either periodically, or in response to a Router Solicitation message. b.) are used by nodes to respond to a Neighbor Solicitation message c.)are used by nodes to determine the link layer address of a neighbor, or to verify that a neighbor is still reachable via a cached link layer address. d.) inquire with Router Solicitation messages to locate routers on an attached link.Routers which forward packets not addressed to them generate Router Advertisements immediately upon receipt of this message rather than at their next scheduled time.

are used by nodes to determine the link layer address of a neighbor, or to verify that a neighbor is still reachable via a cached link layer address. *Reason: Neighbor discovery is a protocol that allows different nodes on the same link to advertise their existence to their neighbors, and to learn about the existence of their neighbors. Routers and hosts (nodes) use Neighbor Discovery (ND) messages to determine the link-layer addresses of neighbors that reside on attached links and to overwrite invalid cache entries. Hosts also use ND to find neighboring routers that can forward packets on their behalf. In addition, nodes use ND to actively track the ability to reach neighbors. When a router (or the path to a router) fails, nodes actively search for alternatives to reach the destination.

When TCP/IP translates a network layer address into a data link layer address, it sends a special ____________ to all computers in the subnet. a.) physical layer packet b.) multicast message c.) X.25 message d.) broadcast message e.)application layer packet

broadcast message *Reason: ARP broadcasts a request packet to all the machines on the LAN and asks if any of the machines know they are using that particular IP address. When a machine recognizes the IP address as its own, it sends a reply so ARP can update the cache for future reference and proceed with the communication.

An endpoint is a a.) locally unused port number for communication b.) a port number c.) combination of an IP address and a port number d.) 16-bit number used to identify specific applications

combination of an IP address and a port number *Reason: A socket is one endpoint of a two-way communication link between two programs running on the network. A socket is bound to a port number so that the TCP layer can identify the application that data is destined to be sent to. An endpoint is a combination of an IP address and a port number.

Network Address Translation a.) operates on a hub, usually connecting two networks together. b.) allows you to use public IP addresses on the internal network. c.) enables private IP networks that use unregistered IP addresses to connect to the Internet. d.) is the feature implemented at Router to protect a network against Denial of Service attack.

enables private IP networks that use unregistered IP addresses to connect to the *Reason: NAT enables private IP networks that use unregistered IP addresses to connect to the Internet. NAT operates on a router, usually connecting two networks together, and translates the private (not globally unique) addresses in the internal network into legal addresses, before packets are forwarded to another network.

A protocol data unit (PDU) is a term used in telecommunications that refers to a.) the language of data transmission b.) information added or removed by a layer of the internet model c.) transport layer protocols d.) the application layer

information added or removed by a layer of the Internet model *Reason: Each layer in the model uses the PDU to communicate and exchange information, which can only be read by the peer layer on the receiving device and is then handed over to next upper layer after stripping.