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1

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2

Frame creation

Destination

MAC

Source

MAC

Source

IP

Destination

IP

Burned

on the NIC

- ARP

- Proxy ARP

- Static

- Dynamic

(RARP ,BOOTP ,

DHCP)

DNS

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3

Source MAC-

Burned

on the NIC

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4

Source IP-

1- by static configuration

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Source IP-DHCP :-

- Dynamic host configuration

protocol

- DHCP allows a host to obtain

an IP address dynamically

without the networkadministrator having to set

up an individual profile for

each device.

- a range of IP addresses on a

DHCP server is defined .

- the entire network

configuration of a computer

can be obtained in one

message from the server.

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Destination MAC-

- ARP :- each PC

form an

ARP tablecontaining

the learned

MACs

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Destination MAC-

A

Router R

Broadcast Message to all:

If your IP address matches B

then please tell me your

Ethernet address

B

A

B

Yes, I know the destination

network, let me give you my

Ethernet address

I take care, to forward

IP packets to B

Proxy ARP :-

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1010

TCP/IP Transport Layer

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Transport Layer Functions

Transport Layer is responsible for the following segmentation of data

error detection

addressing of upper layer application using port numbers

Multiplexing to allow multiple applications to be handled the same connection

support of reliable and unreliable data delivery mechanisms

for reliable data delivery: Establishment of connection (3-way handshake)

Management of connection

reliability (sequencing and acknowledgements)

flow control (Buffering, congestion avoidance, Ready/not ready,

windowing)

error correction (windowing) Termination of connection (4-way handshake)

Transport Layer protocols are

TCP (Transmission Control Protocol)

UDP (User Datagram Protocol)

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Session multiplexing

Segmentation

Flow control (when required)

Connection-oriented(when required)

Reliability (when required)

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Port Numbers

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Connection establishment

Way Handshake :-3

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Multiplexing applications

12.0.0.1

12.0.0.2

13.0.0.1

web server

1

2

3

13.0.0.112.0.0.1 1200 801

13.0.0.112.0.0.1 1500 80

13.0.0.112.0.0.2 1200 80

2

3

Source IP Destination IP Source port Destination port

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Connection management

- Sequencing & Acknowledgement :

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Flow Control

Flow control avoids the problem of a transmitting hostoverflowing the buffers in the receiving host.

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Flow ControlReady / Not Ready :-

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Flow Control

- Windowing (PAR):

2error in

22 2

3

3

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Flow Control- Windowing (PAR):

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Connection termination

way handshake)-4(

Ack, FIN

Ack

Ack, FIN

Ack

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Transport layer protocols

- TCP :

- Transmission Control Protocol

- Connection oriented

- Reliable service

- UDP :

- User Datagram Protocol- Connectionless

- Unreliable service

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TCP Characteristics

Operates at the transport layer of the TCP/IP

stack

Provides applications with access to the

network layer Connection-oriented protocol

Full-duplex mode operation

Error checking Sequencing of data packets

Acknowledgement of receipt

Data recovery features

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TCP Header

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UDP Characteristics

Operates at transport layer of OSI and TCP/IP

models

Provides applications with access to the

network layer without the overhead ofreliability mechanisms ( speedy )

Connectionless protocol

Limited error checking

Best-effort delivery

No data recovery features

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UDP Header

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29

29

Application Layer

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File transfer FTP

TFTP

Network File System

E-mail

Simple Mail Transfer Protocol

Remote login

Telnet

rlogin

Network management

Simple Network ManagementProtocol

Name management

Domain Name System

TCP/IP Application Layer Overview

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Port Numbers

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TCP/IP Protocol Stack