215 Midterm Review

In the physical layer there are:

frames, switches, data links

Internet

interconnection of networks with different network access, has own set of machines and routers

What command provides a list of running processes on our computer?

ps

Header Checksum Field

16 bits. Sender calculates a number based on other bits and places number in the field.

Hosts on the internet have ___ addresses.

2

Trailers are found in which layer?

2, ethernet frames, datalink

What is (are) the well-known port number(s) for FTP? -20 and 21 -25 -80

20 and 21

An 8-bit field can represent ________ alternatives.

256

In the network world the message syntax is composed of ______ parts by default?

3

How long are IPv4 addresses?

32 bits, 4 octet

320,000,000 bps is

320 Mbps

On an Ethernet network, your network address will be your

48 bit MAC address

Ethernet addresses are ________.

48 bits long

MAC Addresses are ______________octets (bytes).

6

If two hosts are separated by seven networks, how many frames will there be along the way when a host transmits a packet to another host?

7

At which layer would you find file transfer protocol (FTP) standards for downloading files?

Application

For human reading, IPv4 addresses usually are expressed in ________. A) hexadecimal notation B) dotted decimal notation C) Both A and B

B

The Internet Protocol is responsible for placing in order packets that arrive out of order. T or F

False

You would use TCP at the transport layer if you did not need error correction or could not use error correction. T or F

False

Client PC's provide service to other client PC's in _____ applications

P2P

______________ data sent in discrete "chunks" (packets); each has a path chosen for it. -circuit switching -packet switching

Packet Switching

Why use UDP?

Packets it as soon as the applicate process writes into the socket. NO DELAY (doesn't have 3 way hand shake)

Which layer process does NOT do encapsulation when an application layer process transmits a message?

Physical

A computer connects to the nearest switch via a

Physical Link

When a switch receives a packet, the switch selects the ________.

Port to send the packet out

A network interface mode that allows you to see every single packet that has been transmitted or received on the interface. -wireshark

Promiscuous mode

The first directory in the file system in Linux

Root directory

What segments only have headers?

SYN and TCP

Host P transmits a SYN to Host Q. If host Q is willing to open the connection, it will transmit a/an ________ segment -Ack -SYN -SYN, ACK

SYN, ACK

The meaning of a message is referred to as the message's ________.

Semantics

[me@linuxbox ~]$ - includes username@machinename -current working directory -$

Shell Prompt-

A program that takes keyboard commands and passes them to the operating system to carry out

Shell or command line

Fragmentation is done on which host?

Source Host

TCP/IP includes UDP. T or F

True

The creation of internetworking required the introduction of 2 addresses for each host. T or F

True

The creation of internetworking required the introduction of two addresses for each host. T or F

True

Using reserved capacity, the data transmission speed for a voice conversation remains constant regardless of how many people are using the system at the same time. T or F

True

How many data links will there be if a frame passes from a computer through two switches, then through a router, then through two more switches, and then to the destination computer -6 -1 -2 -8

Two

What is the command for deleting a user account?

Type in sudo su and user del

connectionless, data messaging service -should be used only when data is not essential (ex: audio/video streaming)

UDP protocol

Types of Ethernet Cables

10BaseT & 100Base T (physical layer)

In binary, the decimal 13 is equivalent to 1101. What is 14?

1110

broadband connection

Analog signaling (more precise)

47,000,000 bps is -47 kbps -47tbps -47 mbps -47 gbps

-47mbps

When a packet passes through seven switches between the source and destination hosts (no routers), the number of physical links is ______, while the number of data links is ____. -1,8 -14, 1 -1, 7 -8,1

-8, 1

IP version 6 addresses are ________. -32 bits long -64 bits long -128 bits long

128 bits long

Which of the following uses packet switching? -dial-up telephone circuits -neither dial up telephone circuits nor leased line circuits -both -leased line circuits

-neither dial up telephone circuits nor leased line circuits

Breaking down a message into many packets is done on the _______ while the reassembly of packets into a message is done on the _______. -both source host and destination host -source host; destination host -destination host, source house

-source host; destination host

A typical packet is about ____ long.

100 bytes

The first 128 characters of the ASCII standard are encoded into binary using ______ bits, however, when any of these characters are stored in a computing environment such as a Host, it's stored as______ bits. Hint: number. -8,8 -8,7 -7,8 -7,7

7,8

What is the well-known port number for HTTP?

80

What layer number is the physical layer? A) 1 B) 2 C) 3 D) None of the above

A

Which of the following is written in dotted decimal notation? A) IPv4 addresses. B) IPv6 addresses. C) Both A and B D) Neither A nor B

A

Data field contains

A TCP segment and UDP datagram.

Ethernet Frame

A term referring to an Ethernet data link header and trailer, plus the data encapsulated between the header and trailer.

IP Packet

AlWAYS has a header and data field. NEVER has a trailer.

commands that we can define ourselves, built from other commands

An alias

What layer number is the data link layer? A) 1 B) 2 C) 3 D) None of the above

B

Which of the following gives you the IP address of a host you wish to communicate with? A) DHCP. B) DNS. C) Both A and B D) Neither A nor B

B

Which of the following is a networked application? A) The Internet. B) The World Wide Web. C) Both A and B D) Neither A nor B

B

Which of the following layers governs transmission across an Internet? A) Layer 2. B) Layer 4. C) Both A and B D) Neither A nor B

B) Transport Layer

Digital signaling that has only one signal (a single signal) on the cable at a time.

Baseband.

Why are there some frames labeled as HTTP under the protocol header after applying the TCP filter?

Because some TCP frames contain HTTP request and response messages.

Which of the following has greater resistance to transmission errors? -Binary Signaling -Analog Signaling

Binary signaling

What are field lengths measured in?

Bits or Bytes "octet"

Transport port fields are found in ? -UDP headers -TCP headers -Both -Neither

Both

"Octet" is another name for

Byte

A device attached to a network is called a ________. A) client B) server C) host D) Either A or B

C

If you did not need error correction or could not use error correction at the transport layer, you would choose ________. A) IP B) TCP C) UDP D) None of the above

C

What layer number is the internet layer? A) 1 B) 2 C) 3 D) None of the above

C

Which of the following is a networked application? A) E-mail. B) The World Wide Web. C) Both A and B D) Neither A nor B

C

Ethernet's MAC policy

CS=carrier sense --> only send data if the medium is idle MA=multiple access--> all can access and send messages CD= collision damage

In P2P applications, most processing is done on the ________. -client -server

Client

Routers used to be called ________. A) IMPs B) switches C) Network Access Points D) gateways

D

What layer number is the transport layer? A) 1 B) 2 C) 3 D) None of the above

D

Which of the following is a host when it is on a network? A) A client PC. B) A server. C) A mobile phone. D) All of the above

D

Which of the following is not a function of a wireless access router? A) Ethernet switch. B) DHCP server. C) Network address translation (NAT). D) DNS server.

D

Applications that use UDP

DNS, multimedia streaming, phone calls, gaming

Contains the packet that the frame is being delivered

Data field

A ________ is the path that a packet takes across a single switched network and its src and dst physical addresses stay unchanged. -transport -physical link -connection -data link -route

Data link

Reassembly is done on which host? -destination -source -both -neither

Destination Host

Routers make packet forwarding decisions based on a packet's _____.

Destination IP address

Command that asks for an IP address for a website

Dig (space) website

A modem converts original ________ signals to ________ signals that can be transmitted through the telephone system.

Digital, Analog

________ is placing a message in the data field of another message. -encapsulation -nesting -encoding -layering

Encapsulation

B7-22-DD-6F-C8-AB is a/an ________ address. -ethernet -IP -TCP

Ethernet

How we connect to a network. Standard defines datalink layer and physical layer connectivity.

Ethernet

Only the __________ has a trailer as a part of the message.

Ethernet Frame

Everything is connected through a switch. Hubs are connected by twisted pair facilitate this topology.

Ethernet Topology: Star

Ethernet Topology: Mesh

Every host is reachable though at least one connection

Broadcast

Everyone in network gets it; all 1s

Ethernet Topology: Star

Everything is connected through a switch. Hubs are connected by twisted pair facilitate this topology.

Ethernet Frames contain error correction and are reliable. T or F

F

The side wishing to close a TCP segment sends a(n) ________ segment. -ACK -SYN -FIN

FIN

A route is the path a frame takes across a single network, from the source host to the destination host, across multiple switches. T or F

False

A switch knows a packet's entire path through a switched network T or F

False

Any home TV must be a " Network Host" ? T or F

False

Ethernet detects errors but does not correct them. Therefore, Ethernet is reliable. T or F

False

Frames are carried inside packets. T or F

False

In terminal-host processing, processing is done on both the terminal and the server. T or F

False

Messages (segments, packets or frames) always have data fields. T or F

False

Spelling internet with a lowercase i indicates you are talking about the global internet. T or F

False

Multicast

First bit is 1; only goes to 1

TCP Close a Connection

Four messages close the connection. --> FYN

Dividing a message into a series of smaller messages is called ____.

Fragmentation

The trailer of an ethernet frame contains what?

Frame Check Sequence (error detection)

Clone that is a complete copy of the VM and is fully independent.

Full clone

Used to facilitate shared connections

Hubs

Which network standard deals with addresses and functionality for routers to move packets across an Internet? -IP -TCP -UDP

IP

Which network standard governs the hop-by-hop (a hop is host to router or router to router) transmission of packets across an internet? -IP -TCP -UDP

IP

Which standard deals with addresses and functionality for routers to move packets across an internet?

IP

What command displaces information about all network interfaces currently in operation?

Ifconfig

Provides unreliable, unordered, connectionless service.

Internet Protocol

Which type of circuit typically operates at faster speeds?

Leased circuit lines

Clone that uses a reference to the original VM, requires less disk space, and cannot run without access to the original

Linked Clone

First thing received on receiver end. Data field contains the content being delivered. Header is everything before data field.

Message Syntax

connectionless protocol

No connection required between sender and receiver. Can easily lose packets. Useful for periodic burst transfers.

Which of the following places a heavier burden on the internet? -TCP -Ip -UDP

TCP

Which standard corrects errors?

TCP

Which standard does fragmentation?

TCP

Which standard places packets that arrive out of order in order? -IP -TCP -UDP

TCP

always have headers, some don't have data fields, never trailers

TCP Segment

connection oriented, stream of bytes service, reliable, flow/congestion control.

TCP protocol

When your PC requests an IP address from a DNS (Domain Name System), the DNS responds with a message containing the IP address of __________.

The host your trying to reach

What does it mean if the last character of the prompt is a # sign?

The terminal session has superuser privileges.

error detection, doesn't correct, can only discard frame

Trailer

Ethernet Frame contains

Trailer, Header, and data field

Which layer governs the transmission of packets across an internet?

Transport Layer, Network Layer

Which layer governs end-to-end transmission between two hosts across an internet?

Transport layer

A network is a system that permits networked applications on different hosts to work together. T or F

True

A smart phone connected to an internet is a host. T or F

True

All binary signaling is digital signaling. T or F

True

Each layer provides services to the layer above it. T or F

True

Headers usually are divided into fields. T or F

True

In cloud computing, server management is outsourced. T or F

True

In general, same local network address equals the same data link. T or F

True

Multiplexing reduces transmission cost. T or F

True

command to copy files and directories

cp

Packets are carried inside frames. T or F

True

Circuits are reasonably efficient for ________ transmission.

Voice

Inside a computer, data is represented as -decimal -hexadecimal -binary

binary

Network speeds usually are measured in ________.

bits per second

In client/server processing, processing is done on the ________. -neither client nor server -both client and server -server -client

both client and server

command- change directory

cd

Frequency division multiplexing (FDM) is an example of sharing bandwidth under ______________________.

circuit switching

An internet

connection of networks interconnected by layer 3 switches/routes

Requires a session connection be established before any data can be sent. "reliable." and guarantees that data will arrive in the same order

connection-oriented protocol

Which of the following have explicit openings and closings? -connectionless protocols -connection-oriented protocols -both -neither

connection-oriented protocols

After the internet "Network" layer process does encapsulation, it passes the IP packet to the ________ layer process. -physical -transport -data link -application

data link

What command creates a textile?

edit

Converting application messages (consist of characters) into bits is called ________. -encapsulation -encryption -encoding -conversion

encoding

Programs that can be compiled binaries. ex python

executable program

command- list directory contents

ls

For bursty data, packet switching is desirable because it ________. -makes transmission more efficient -reduces transmission time -both -neither

makes transmission more efficient

command that displays a programs manual prage

man

command to create directories

mkdir

The _______ is often drawn as a cloud to emphasize that the user does not need to know what is going on internally.

network core

If the destination host receives a segment that is incorrect, it will ________. -transmit an ACK segment -transmit a NAC segment -transmit an RSND segment -none of these

none of these

command that displays the DNS and ip address

ns lookup

If two hosts are separated by seven networks, how many packets will there be along the way when a host transmits a packet to another host?

one

After the side wishing to close a TCP connection sends a FIN message, it will ________. -not send any more segments -only send ACK segments -only send FIN segments

only send ACK segments

In the network layer there are

packets, routers, routes

In internets, different networks are connected by

routers

An HTTP message is encapsulated at the transport layer to become a TCP ___________ , which in turn is encapsulated at the internet layer to become an IP ________ , which in turn it's encapsulated at the data link layer to become an Ethernet _________ .

segment, packet, frame

How a message is organized is its ________. -syntax -semantics -order

syntax

The header of an ethernet frame contains what?

the MAC address

In TCP, which process decides whether to retransmit a lost or damaged segment—the original sender or the receiver?

the original sender

UDP checks messages for errors but does not correct them. UDP is ________. -reliable -unreliable -connection-oriented

unreliable