IST 220 Worksheet 6-14

Class B of IP address allows ______ host IDs per network.

(2^14)-2

Class A of IP address allows ______ host IDs per network.

(2^24)-2

Class C of IP address allows ____ host IDs per network.

(2^8)-2=254

TCP stands for

Transmission Control Protocol

TCP/IP stands for

Transmission Control Protocol/Internet Protocol

The left most bit of class A IP address is reserved and indicated by a __ - leaving 7 bits for network ID.

0

What is meant by a "dynamic leased IP address"

1. We call it dynamic because each time when you connect to the network, the IP add may change (ie., assign an IP address at run time by the DHCP server). 2. We call it leased because each dynamic IP address has a certain time period. When time expires, the IP add will return to the IP address pool unless the leased is renewed

Class A of IP addresses range from

1.0.0.0-127.255.255.255

Two left most bits of class B IP address is reserved and indicated by a ___- leaving 14 bits for network ID.

10

Two left most bits of class C IP address is reserved and indicated by a ____ - leaving 21 bits for network ID.

110

Class B of IP addresses range from

128.0.0.0-191.255.255.255

Class C of IP addresses range from

192.0.0.0-223.255.255.255

________ divides the data received from the application layer into fixed size of messages.

Transport Layer

In class B of IP address, we can have ______ network IDs.

2^14

In class C of IP address, we can have _____ network IDs.

2^21

In class A of IP address, we can have _________ network IDs

2^7 = 128

MAC address is a unique ____ bits binary address

48

IP adresses are divided into __ classes

5

________is one of the layers in the TCP/IP reference model that provides end-to-end message reliability (i.e., reliable delivery of messages all the way from source host to destination host)

Transport Layer

A Web Server is an example of a publically reachable host that must have a unique public IP address.

True

T/F-A class B IP address can be assigned to an organization that wants a network of 6000 hosts.

True

T/F-Each device must have its own unique IP address so that it can be uniquely identified on the public Internet.

True

T/F-If the message size is larger than the smallest MTUs of intermediate networks, original message needs to be fragmented into smaller packets or frame.

True

T/F-In CIDR, Network portion (i.e., Network ID) of an IP addresses does not have to 1 bytes, 2bytes, or 3bytes

True

T/F-In CIDR, Network portion of an IP address can be any number of bits.

True

T/F-In CIDR, number of bits in the host ID can be further divided down to create smaller networks (i.e., the subnet)

True

T/F-Private IP addresses are assigned to devices that exist within a private data network.

True

T/F-Private IP addresses are referred as non-routable addresses

True

T/F-Private IP addresses do not have to be unique on the Internet (i.e., the public network)

True

T/F-Public IP addresses are assigned to devices that are directly connected to the Internet (e.g., a web-server)

True

T/F-Transmitting a large message (i.e., significant number of bytes per message) will typically occupy the shared channel for a longer period of time.

True

T/F-UDP is a transport layer protocol that delivers the data at much faster rate than the TCP.

True

What are the two types of fragmentation and how they differ?

Two types are : Host fragmentation versus IP fragmentation - In host fragmentation, source host divides the outgoing data packet into smaller fragments and the destination host will reassemble the fragments back into the original packets. - In IP fragmentation, intermediate router(s) perform the same task.

Define protocol in the context of computer network.

A protocol is a set of rules that define how the data is going to be exchanged b/w the 2 communication entities.

___________is used to resolve an IP address into a MAC address.

ARP

ARP stands for

Address Resolution Protocol

Write one advantage and one disadvantage of Host based fragmentation over IP fragmentation

Advantage-fragmentation and defragmentation needs to be done only once. Disadvantage-put extra computational burden on the source/destination hosts.

UDP stands for

User Datagram Protocol

A single hexadecimal digit can represent _____ binary digits

four

_________ is the top most layer of the TCP/IP reference model

Application Layer

________is one of the layers in the TCP/IP reference model that provides support to variety of users applications and protocols running at the top most layer of the TCP/IP reference model.

Application Layer

________provides an interface to end-users, so that end users can interact with rest of the layers of the TCP/IP reference model

Application Layer

________is a Link layer (also called network interface layer) device.

Both bridge and switch

CIDR stands for....

Classless Inter Domain Routing

CIDR stands for

Classless Inter-domain routing

Worksheet 2 Number8,9,10

Converting to hexadecimal

________is an application layer protocol that assigns leased IP addresses to devices at run time.

DHCP

Who assigns private IP addresses to devices that exist within a private data network

DHCP server of a gateway router

Where a wireless router get its public IP address

DHCP server of an ISP

_________ is an application layer protocol use to resolve/convert an Host Name into an IP address

DNS

____________________is used to resolve a host name into an IP address.

DNS

DNS stands for

Domain Name System

DHCP stands for

Dynamic Host Configuration Protocol

EUI stands for

Extended Unique Identifier

What are some common multiplexing schemes?

FDM, TDM, SDM, CDM.

_________is an application layer protocol that allows users to transfer data files from one computer to others.

FTP

T/F-A Class C IP can be assigned to an organization that wants a network of 500 hosts.

False

T/F-ARP is used to resolve a MAC address into a 32 bit IP address.

False

T/F-Class A IP address allows to have only 256 hosts per network

False

T/F-DHCP assigns leased static IP addresses to devices at run time

False

T/F-In CIDR, an IP address is expressed in the following dotted decimal format: a.b.c.d

False

T/F-Switch is an Internet layer device that examines the header of each packet to determine its destination IP address.

False

T/F-Telnet is an application layer protocol that allows users to connect to a remote server over a secure tunnel.

False

T/F-The probability of getting an error is less if we transmit significantly large number of bytes per message (i.e., no use of fragmentation).

False

T/F-UDP is a transport layer protocol that offers reliable delivery of user data all the way from the source host to the destination host.

False

FTP stands for

File Transfer Protocol

Define when message fragmentation needs to be done.

Fragmentation needs to be done if the size of an outgoing data packet is greater than the MTU of any intermediate networks

_________ is a communication protocol that works with the web browsers to allow users to access web pages stored on the webs servers.

HTTP

HTTP stands for

Hyper Text Transfer Protocol

__________is an Internet layer protocol that is used for error reporting.

ICMP

________ is used for transmitting the datagrams from one network to another until it gets to the destination network.

IP

____________is used at the Internet layer of the TCP/IP reference model

IP addressing

Discuss how fragmentation helps in minimizing the transmission overhead.

Instead of sending the large message of 5000 Bytes, you decided to fragment the message into smaller packets. For example, you divide then in 10 smaller message each one containing only 500 Bytes. In this case, it is likely that only one Fragment (Packet) or 2 two packets will be in error (not the entire message of 5000 Bytes). That is only Packet 4 need to be retransmitted (i.e., 500 Bytes).

IANA stand for...

Internet Assigned Numbers Authority

________ layer adds its own header and trailer to specify start and end of each data frame

Internet Layer

________may divide the TCP segments into smaller packets (i.e., IP Datagrams).

Internet Layer

IP stands for

Internet Protocol

Discuss how the use of fragmentation maximizes the advantages of multiplexing

It maximizes the advantages of multiplexing by sending small size data packets and therefore not one user can occupy the channel for a longer period of time, which will also improve the "fairness" in the network environment (i.e., every users is getting an equal chance to transmit the data using the shared multiplexed channel).

MAC address is also known as _______ address.

LAN, Physical, NIC, Ethernet, and EUI

________ is responsible to deliver the data packets from one hop to another hop until the data packets reach to the network for which the destination host is attached

Link

____________is used at the Link Layer of the TCP/IP reference model

MAC addressing

MTU stands for...

Maximum Transmission Unit

MAC stands for _____

Medium Access Control

Class D of IP address is reserved for

Multicasting

What is multiplexing?

Multiplexing: Another reason for transmitted small fragments over a communication channel is to maximize the multiplexing. What Multiplexing means - a single communication channel is shared among multiple users so that every user can transmit data simultaneously. However, when multiple users share a common channel, there should be some method to avoid collision. For that, we have different multiplexing schemes: FDM, TDM, SDM, CDM.

NAT stands for

Network Address Translation

NIC stands for _______

Network Interface Card

_______ Reference model has 7 layers.

OSI

Define the purpose of a three way handshake protocol

One simple definition is "A three-way-handshake is a method used in a TCP/IP network to create a connection between a local host/client and server. It is a three-step method that requires both the client and server to exchange SYN and ACK (acknowledgment) packets before actual data communication begins" from

OSI stands for

Open System Interconnection

________is one of the layers in the TCP/IP reference model that transmits the data at the byte levels using the communication channel

Physical

_____________is used at the Transport layer of the TCP/IP reference model

Port Addressing

PDU stands for

Protocol Data Unit

_________is a physical layer device.

Repeater

_________is an Internet layer device.

Router

Discuss the difference between Router and a Switch (use internet to find more information).

Router is used as an Internet layer device; transmission of data packets Switch is used as a link layer device; provides forwarding functionality for the hops

__________is an application layer protocol that allows users to securely connect to a server remotely over an insecure network.

SSH

SSH stands for

Secure Shell

_________is an intermediate device that provides forwarding functionality to move the data from one hop to other.

Switch

__________ is referred as a connection oriented protocol that provides end to end message reliability

TCP

______________ is used by HTTP to establish a secure/reliable connection between 2 hosts.

TCP

What messages are exchanged during the three way handshake protocol

TCP will use its Three-Way Handshake Protocol to establish a Connection. a. Source Host will send the Connection Request (in TCP Packet with SYN Bit set to 1 - this will indicate that source host wants to establish a connection with the Starting Sequence Number). b. Server will send the +ACK in response to the SYN packet. Will also send its expected Sequence Number in the SYN bit. So the following message will be sent SYN, ACK c. Finally, the Source Host will send the ACK to acknowledge the received SYN bit from the Server. Once, we are done with this, HTTP Request will arrive at the Server. Server will get back to the Source Host with the desired page.

Discuss the differences between TCP and UDP. Give an example to show which protocol should be used for different applications.

TCP-connection oriented protocol that provide end-to-end msg reliability;header is 20 bytes UDP-connectionless oriented protocol that transit msgs as fast as possible;header is 8 bytes.

______ Reference model has 5 layers.

TCP/IP

________ is a user command program that allows users to remotely connect to a server over an insecure network (i.e., the Internet)

Telnet

2. Each network has its own MTU that specifies ________________ that can be passed through that network.

maximum number of bytes