Telecom Final

a message must have data

false

a message must have a trailer

false, except in a data link! (ALL DATA LINKS HAVE TRAILERS)

In a single network, packets are called...

frames

Dumb terminal example

host in the back of the room

uptime

how long something has been running

Which phase of the plan-protect-respond cycle takes the largest amount of work?

protect

In symmetric-key encipherment uses a ____ secret key for both _____ and decryption.

shared, encryption

Breaking down a message into many packets is done on the _______ while the reassembly of packets into a message is done on the _______.

source host, destination host

command to open a VM

sudo vmware

how do you delete a user?

userdel lab1

Viruses most commonly spread from one computer to another ________.

via email

peer to peer computing

video games,

ps all

view current running process, shows pid (process id)

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?

2

What is (are) the well-known port number(s) for FTP?

20 and 21

An 8-bit field can represent ________ alternatives.

256

How long are IP (version 4) addresses?

32 bits long

How long are IP addresses (Ver4)?

4 Bytes

47,000,000 bps is

47 Mbps

Ethernet addresses are ________.

48 bits long

MAC Addresses are ______________octets (bytes).

6

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.

7,8

Hacking is defined as intentionally using a computer resource without authorization or in excess of authorization.

FALSE

Hacking is intentionally of using a computer resource with authorization.

FALSE

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

False (not always have data fields)

After the side wishing to close a TCP connection sends a FIN message, it will ________.

Only send ACK messages

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

Packing switching

Which is the simplest error detection technique:

Parity bit

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

Physical

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

Physical (first one)

OSI is almost 100% dominant at the...

Physical and data link layers

Which is less expensive to implement?

SSL/TLS

Host P transmits a SYN to Host Q. If host Q is willing to open the connection, it will transmit a(n) ________ segment.

SYN/ ACK

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

Semantics

Tricking users into doing something against their interests is ________.

Social engineering

UDP checks messages for errors but does not correct them. UDP is

UNRELIABLE

A ________ is the path that a packet takes across a single switched network and its src and dst physical addresses stay unchanged.

data link

After the internet "Network" layer process does encapsulation, it passes the IP packet to the ________ layer process.

data link

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

1110

IP version 6 addresses are ________.

128 bits long

can checkout adduser?

No, only root can adduser by typing man adduser adduser lab1

In ________parity, the total numbers of 1's including the parity bit should be Odd.

ODD

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?

1

If using Odd parity, What should be the parity bit for the following stream: 11101011

1

how many bits in a byte

8 bits in a byte

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

8, 1

difference between USB and CD in a VM?

A USB can only be used by one at a time, while a CD can be used by the host and the VM.

To find the MAC address of a specific IP number in your network, the network runs

Address Resolution Protocol ARP

Ethernet uses _____topology

BUS

Which of the following has greater resistance to transmission errors?

Binary signaling

In the asymmetric-key cryptography, if Alice is the sender and Bob is the recipient, then Alice encrypts her plain-text message using ______ key and Bob decrypts Alice's ciphertext using his own _____ key.

Bob's, Private

Transport port fields are found in ________.

Both UDP and TCP headers

Which of the following can be a type of backdoor?

Both a new account and a trojan horse

Digital signature provides message-by-message ________.

Both integrity and authentication

The CRC technique uses:

Both shift register and XOR unit

Attack programs that can be remotely controlled by an attacker are ________.

Bots

A password cracking attack that tries all combinations of keyboard characters is called a ________.

Brute force attack

Which is the most complex error detection technique?

CRC

Lab 1- What does the tilda stand for? ~

Change the directory

A specific encryption/decryption algorithm is known a ________.

Cipher

What is more reliable? Circuit or packet switching?

Circuit because a packet might drop it

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

Circuit switching

If two computer sends frames at the same time in an Ethernet network, ____occurs.

Collision

Which of the following have explicit openings and closings?

Connection oriented protocols

Which of the following is not one of the four response phases for when attacks occur?

Detecting the attack. Repairing the damage. Punishing the attacker. Stopping the attack. All of these are response phases.

If the destination host receives a segment that is incorrect, it will ________.

Do nothing

After a break-in, the first step usually is to ________.

Download a hacker kit

Converting application messages (consist of characters) into bits is called

ENCODING

________ is placing a message in the data field of another message.

Encapsulating

Which of the following is considered a service provided by the Data Link Layer?

Error Detection, Flow control, half and full duplex

Checksum is a methodology of _______________________

Error detection

B7-22-DD-6F-C8-AB is an ________ address.

Ethernet

An attack that occurs before a patch is available is called a zero-day attack.

FALSE

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

FALSE

It is generally illegal to write malware.

FALSE

Most hackers today are driven by curiosity, a sense of power, and, sometimes, a desire to increase their reputation among peers.

FALSE

Layer 2 packet is called a

FRAME

Any home TV must be a " Network Host" ?

False

What happens in the application layer?

HTTP protocol, browser CREATES a message

A __________ is considered as a Physical Layer Device.

Hub

Network Layer

IP address

Which has stronger security?

IPsec (not ssl/tls)

Users typically can eliminate a vulnerability in one of their programs (such as an operating system) by ________.

Installing a Patch

Data Link Layer

MAC Address

Computer security incident response teams (CSIRTs) are used in ________.

Major incidents

Which of the following uses packet switching?

Neither dial-up nor leased line circuits

Mobile code is another name for ________.

Neither worm nor virus

How a message is organized is its ______

Syntax

Which standard places packets that arrive out of order in order?

TCP

What happens in the transport layer?

TCP and UDP, WHICH app is running/ send this packet?

two major standard architectures

TCP/IP and OSI

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

TRUE

Malware is a generic name for evil software.

TRUE

Packets are carried inside frames.

TRUE

Scripts (Mobile Code) may execute software when a webpage is downloaded. However, they are likely to be dangerous only if a computer has a vulnerability.

TRUE

slots in a bandwidth are not shared

TRUE

Physical Layer

Transcribes it to BINARY

What layer are TCP and UDP in?

Transport

The tool used for network protocol analyzer is called ______________

Wireshark

what does not have a data field ?

a TCP syn statement

TCP is...

a connection oriented, meaning there is a formal opening and closing, 3 handshake

Linked vs full clone

a linked clone will not work unless the original is there. a full clone will.

The network core

a mesh of interconnected routers

What must a data link have other than a header?

a trailer

virtualization is...

anything that is not one a local host

how to bring up python in the lab

apt-cache search python igrep

Inside a computer, data is represented as

binary

In client/server processing, processing is done on the

both client and server

Cryptographic systems provide ________.

both confidentiality and message integrity

Data Link Layer can detect errors using _________

checksum, CRC, parity bit

In P2P applications, most processing is done on the

client (who sometimes plays as a server)

Tcp is

connection oriented and Reliable

is HTTP connection oriented or connectionless?

connectionless. TCP is connection-oriented.

reservation

dedicated fraction of available bandwidth

ifconfig

displays all network interfaces currently running, will show you your ip address

client/ server example

email, facebook, twitter

Doubling the time backoff value each time a collision happen is called

exponential backoff

what does ctrl + c do?

it exits out of something to go back to checkout

suspending a VM

like putting a regular computer alseep

resources

link bandwidth

ls -al

lists the files in the working directory

For bursty data, packet switching is desirable because it ___

makes transition more efficient

How do you verify that Ubuntu has network access?

man ping (ping the internet)

cloud computing

not on a local machine, outsourced

In the internet, packets are called

packets

Actions that people are allowed to take on a resource comes under the heading of ________.

permissions

In a threat environment, you should ____________ then _______________then ________________.

plan, protect, respond

In digital signature, the signer Alice uses her ___ key to sign a document. The verifier Bob, on the other hand, uses Alice's _____ key to verify the document.

private, public

DoS (Denial of Service) attacks attempt to ________.

reduce the availability of a computer (such as a server)

Balancing threats against protection costs is called ________.

risk analysis

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

what are the two numbers in a header?

the source and destination IP addresses

Headers usually are divided into fields.

true

standards

way of communicating between entities

pwd

where you are or your current directory

Address field within the header

who to send the message back to

How do you share a folder between a VM and a host?

you go to options, share folders, and make sure that folder sharing is enabled.

_rw-r--r--

yourself, the group, other. Read right execute