EXAM
Name Servers
-DNS (Domain Name System) name servers are organized in a hierarchical structure. -Last part of an FQDN is called the top-level domain (TLD).
The seventh layer of the OSI model is the _______________ layer.
Application
Consider a router which you are deploying. Which layer of TCP/IP model is not used?
Application layer
Which layer of the TCP/IP layers is the combination of 3 layers?
Application layer
socks
Consists of host's IP address and the port number of an application running on the host Colon separates the two values. Example—10.43.3.87:23
___________ assigns IP addresses.
DHCP
Flow Control: Window-Size Example
During the three-way handshake, the receiver informs the sender of the buffer size it allocated for the sender. That is the size of the Receiver buffer (rwnd)
Port numbers used by TCP/UDP
Ensure data is transmitted to the correct process among multiple processes running on the computer.
TCP provides__________ to prevent sender from over-running receiver buffers.
Flow control
2001:db8:3333:4444:5555:6666:7777:8888 is an ____________ address
IPv6
10:00:5A:0C:53:AF is a _____________ address
MAC
Fields in a TCP Segment port number
Ports plus IP addresses are used to identify a connection (refer to chapter 2 and the discussion of the port number and the IP address and socket)
Fields in a TCP Segment acknowledgment
The value of the acknowledgment field in a segment defines the number of the next byte a party expects to receive. *acknowledgment number is cumulative.*
Which layer of TCP/IP is used to pack data into data packets known as IP datagram's, which contain source and destination address information that is used to forward the datagram between hosts and across networks?
Transport layer
Which layer of TCP/IP permits devices on the source and destination hosts to carry on a conversation?
Transport layer
_________ is a protocol responsible for delivering data across network connections.
UDP
what are the flags in a TCP segment.
URG: URGENT POINTER is valid Ack: acknowledgement is valid PSH: pass the data to the application immediately RST: rest or abort the connection syn: set/ synchronize a connection FIN: terminate the connection
Port numbers are divided into three types:
Well-known ports - 0 to 1023 Registered ports - 1024 to 49151 Dynamic and private ports - 49152 to 65535
wan
a group of LANs spread over a wide geographical area ■ Spans a region of 100,000 km radius: state, country, continent. ■ Internet is the largest WAN
Lan
a group of computers and associated devices connected to a server within a distinct geographic area such as an office or a commercial establishment.
MAN
a group of connected LANs in the same geographical area■ connect two or more LANs ■ span in a range of 5 - 50 km in diameter
An IP address consists of ___________
a network part in high order bits and a host part in low order bits
What is the benefit of Networking? a) All the given choices are correct b) Easier access to Resources c) File Sharing d) Easier Backups
a) All the given choices are correct
0001:0000:0000:0000:4A12:0061:0000:D3C5 can be simplified to ___________ (select the best answer) a) 1::4A12:61:0000:D3C5 b)1::4A12:61:0:D3C5 c) 1::4A12:61::D3C5 d) 1:0:0:0:4A12:61:0:D3C5 e) 1:0000:0000:0000:4A12:61::D3C5
b) 1::4A12:61:0:D3C5
During the second transmission in the three way handshake, which flag(s) is(are) set?
both ACK and SYN
what are the concepts of transmission.
broadcasting, multicasting, any casting, unicasting
A host may obtain an IP address _____________
by dynamically requesting one from a suitable server
Classes based on Addressing of First Octet Value
class A: 0-127, 1 network and 3 host. class B: 128-191, 2 network and 2 host. class C: 192- 239, 3 network and 1 host
200.1.34.254 is a class _____ IP address class: A class: C class: B Class: D
class: c
MAC Address is needed at the ______ layer of the TCP/IP model
data Link
MAC Address is needed at the ______ layer
data link
In networking, adding a header to the data before transmission is called ___________
encapsulation
The addition of control information to a packet as it moves down through the layers is called ________________
encapsulation
A point to point link refers to a direct connection between two computers on a network. true/ false
false
In a client server network model there is no centralized control. true/ false
false
The size of the TCP sliding window (rcwd) stays constant throughout the duration of the connection. TRUE/false
false
when a client requests a web page from a server, the following protocol is used.
http
Expand WAN
wide area network
how to close a TCP session
• A sends B a packet with the FIN bit set (a FIN packet), announcing that it has finished sending data • B sends A an ACK of the FIN • When B is ready to cease sending, it sends a FIN to A • A sends B an ACK of the FIN
two types of IP addresses
■ IPv4—A 32-bit address ■ IPv6—A 128-bit address
Simplifying IPv6 Address
- Leading zeros in a four-character hex block can be eliminated - If a block contain all zeroes, they can be written as double colons (::), only one set of double colons is used in an IP address 0001:0000:0000:0000:4A12:0061:0000:D3C5 ⬇ 1::4A12:61:0:D3C5
each flag take how many values
1 or 0 if the segment sent has the ack flag equal to 1, it means the segment is an acknowledgement of the previously sent segment.
IPv6 - 128 bit address 2001:db8:3333:4444:5555:6666:7777:8888
128-bits written in 8 blocks of hexadecimal separated by colons; Blocks are 16 bits each
Internet (Network) layer is the ____layer of TCP/IP layer model.
2nd
IPv4 - 32 bit address 192.168.1.2
32-bit address organized in four groups of 8 bits each (octets) Each octet can be any number from 0-255
How many layers are in TCP/IP model?
4
Transport layer is the _____ layer of OSI model.
4th
How many extra messages do you have to transmit (at least) if you use TCP protocol instead of UDP?
7
Fields in a TCP Segment Sequence number
Sequencing ■ Messages don't always arrive in the same order they were created, TCP attaches a chronological sequence number to each segment so the destination host can, if necessary, reorder segments as they arrive
Transmission Control Protocol (TCP) flow control
TCP provides Flow control ■ Flow control - gauges rate of transmission □ TCP adjusts the size of the sliding window (rwnd) ■ This is the purpose of the Advertised Window field
Define transmission control protocol (TCP)
is a connection- oriented protocol. it ensures that a connection or session is established by using a three step process called a three way handshake
what are the types of computer networks
lan, man, wan, pan
what are the four addressing method layers?
layer 1: datalink: mac address layer 2: internet: IP address layer 3: transport: port number layer4: application: FQDN (FULLY QUALIFIED DOMAIN NAME
what are the seven layers of OSI?
layer 1: physical layer 2: data link layer 3: network layer 4: transport layer 5: session layer 6: presentation layer 7: application
A _____ is a device that forwards packets between networks by processing the information included in the packet
router
______ topology consists of a central hub or a switch that connects nodes. This is one of the easiest networks to setup and maintain.
star
what are the steps to a three way handshake
step 1: request for a connection (syn) step 2: response to the request (syn, ack) step 3: connection established (ack)
The TCP operates in the _______layer of the TCP/IP model.
third
What is the three-way handshake?
three transmissions are sent before the data is transmission.
A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other. true/false
true
A protocol is a set of rules that ensure and define communication between two or more devices over a network. true / false
true
LAN is short for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location. Correct! True / False
true
