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