Networking Concepts (2) Flashcards
What is the valid range of numbers for the well-known Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) ports used by servers?
1 through 49151
49152 through 65534
1 through 1023
1 through 1023
Well-known TCP and UDP server ports fall in the range of 1 through 1023. Registered port numbers fall in the range from 1024 to 49151. Ephemeral client ports fall in the range of 49152 through 65535
Ralph is a network administrator who has just installed a new open source email server for the users at his company. The server is configured to send and receive Internet email and create a mailbox for each user that will permanently store the user’s mail on the server. Ralph next uses a protocol analyzer to examine the network traffic resulting from the new server installation. Which of the following new protocols should Ralph expect to see in his network traffic analysis? (Choose all correct answers.)
SNMP
SMTP
POP3
IMAP
SMTP
IMAP
Ralph’s traffic analysis should show the addition of the Simple Mail Transfer Protocol (SMTP), which handles incoming and outgoing Internet mail, and Internet Message Access Protocol (IMAP), which provides mailboxes for users who store their mail permanently on the server. POP3 is a mailbox protocol that enables users to download their messages and should therefore not be present on the network. SNMP is a network management protocol and RIP is a routing protocol; neither of them carries email traffic
Which of the following values could a web client use as an ephemeral port number when communicating with a web server?
1024
1999
50134
50134
An ephemeral port number is a temporary port supplied by a client to a server, for use during a single session or transaction. The allowed ephemeral port number values range from 49152 to 65535. The port values below 1024 are reserved for use as well-known ports, and the values from 1024 to 49151 are reserved for ports registered by specific manufacturers for their applications. Of these answers, 50134 is the only value that the client can use as an ephemeral port
Which of the following protocols provides connection-oriented service with guaranteed delivery at the transport layer of the OSI model?
TCP
HTTP
UDP
TCP
The Transmission Control Protocol (TCP) provides connection-oriented service at the transport layer, with guaranteed delivery. The User Datagram Protocol (UDP) provides connectionless service at the transport layer. Hypertext Transfer Protocol (HTTP) operates at the application layer, and Internet Protocol (IP) is a connectionless network layer protocol
Which of the following protocols is limited to use on the local subnet only?
Address Resolution Protocol (ARP)
Dynamic Host Configuration Protocol (DHCP)
Domain Name System (DNS)
Address Resolution Protocol (ARP)
ARP relies on broadcast transmissions, which are not routable. It is therefore limited to use on the local subnet. DHCP also relies on broadcasts, but the ability to create DHCP relay agents makes it usable on an entire internetwork. DNS and SMTP do not rely on broadcasts and are therefore not limited to the local subnet
At which of the following layers of the Open Systems Interconnection (OSI) model do the protocols on a typical local area network use MAC addresses to identify other computers on the network?
Physical
Data link
Network
Data link
The Ethernet (or IEEE 802.3) protocol at the data link layer uses MAC addresses to identify computers on the local network. Media access control (MAC) addresses are coded into the firmware of physical network interface adapters by the manufacturer. The physical layer deals with signals and is not involved in addressing. The IP protocol at the network layer has its own addressing system. The transport layer protocols are not involved in addressing
Which of the following organizations developed the Open Systems Interconnection (OSI) model?
American National Standards Institute (ANSI)
Institute of Electrical and Electronics Engineers (IEEE)
International Organization for Standardization (ISO)
International Organization for Standardization (ISO)
ISO developed and published the OSI model to serve as a conceptual model for software and hardware developers. The ITU-T, formerly known as the CCITT, coordinates the development and advancement of international telecommunication networks and services. ANSI is a private organization that administers and coordinates a United States–based standardization and conformity assessment system. The IEEE publishes standards that define data link and physical layer standards. These standards are referred to collectively as the 802 series
Which layer of the Open Systems Interconnection (OSI) model is responsible for the logical addressing of end systems and the routing of datagrams on a network?
Physical
Data link
Network
Network
Network layer protocols specify logical addresses for end system communication and route datagrams across a network. The physical layer defines standards for physical and mechanical characteristics of a network. The data link layer uses media access control (MAC) or hardware addresses, not logical addresses. The transport layer uses port numbers, not logical addresses. Session layer protocols create and maintain a dialogue between end systems. Presentation layer protocols are responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network
What layer of the Open Systems Interconnection (OSI) model is responsible for translating and formatting information?
Transport
Session
Presentation
Presentation
The presentation layer implements functions providing formatting, translation, and presentation of information. No other layers of the OSI model translate and format application data
Which of the following devices typically operates at the network layer of the Open Systems Interconnection (OSI) model?
Proxy server
Hub
Router
Router
A router connects networks together at the network layer of the OSI model. Proxy servers operate at the application layer. Network interface adapters operate at both the data link and the physical layers. Hubs are physical layer devices
Which layer of the Open Systems Interconnection (OSI) model provides an entrance point to the protocol stack for applications?
Session
Presentation
Application
Application
The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network. All other layers of the OSI model reside below this layer and rely on this entry point
Which layer of the Open Systems Interconnection (OSI) model is responsible for dialogue control between two communicating end systems?
Network
Transport
Session
Session
The session layer is responsible for creating and maintaining a dialogue between end systems. This dialogue can be a two-way alternate dialogue that requires end systems to take turns transmitting, or it can be a two-way simultaneous dialogue in which either end system can transmit at will. No other layers of the OSI model perform dialogue control between communicating end systems
Some switches can perform functions associated with two layers of the Open Systems Interconnection (OSI) model. Which two of the following layers are often associated with network switching? (Choose all correct answers.)
Physical
Data link
Network
Transport
Data link
Network
The primary function of a switch is to process packets based on their media access control (MAC) addresses, which makes it a data link layer device. However, many switches can also perform routing functions based on IP addresses, which operate at the network layer
At which layer of the Open Systems Interconnection (OSI) model are there TCP/IP protocols that can provide either connectionless or connection-oriented services to applications?
Physical
Network
Transport
Transport
There are two types of transport layer protocols: connection-oriented and connectionless. Connection-oriented protocols guarantee the delivery of data from source to destination by creating a connection between the sender and the receiver before any data is transmitted. Connectionless protocols do not require a connection between end systems in order to pass data. The physical layer does not use connectionless or connection-oriented protocols; it defines standards for transmitting and receiving information over a network. The data link layer provides physical addressing and final packaging of data for transmission. The network layer is responsible for logical addressing and routing. The session layer is responsible for creating and maintaining a dialogue between end systems. The presentation layer is responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network
Which of the following layers of the Open Systems Interconnection (OSI) model typically have dedicated physical hardware devices associated with them? (Choose all correct answers.)
Physical
Data link
Network
Transport
Session
Presentation
Application
Physical
Data link
Network
The physical layer of the OSI model is associated with hubs, cables, and network interface adapters. The data link layer is associated with bridges and switches. The network layer is associated with routers. The transport, session, presentation, and application layers are typically not associated with dedicated hardware devices
