The IP Networks. Introduction to Computer Networks Chapter 2 Part 3 of 3 CA M S Mehta, FCA

Transcription

1 The IP Networks Introduction to Computer Networks Chapter 2 Part 3 of 3 CA M S Mehta, FCA 1

2 The IP Networks Learning Objectives Task Statements 1.1 Identify deployment of different components of IT and their functions..networks Knowledge Statements 1.2 Fundamental concepts of different components of IT and their functions..networks 2

3 The IP Networks Topics Covered IP Networks Network Services On-demand Computing Factors Impacting Quality of Network Services 3

4 What are IP Networks 4

5 IP Networks An IP network is a communication network that uses Internet Protocol (IP) to send and receive messages between one or more computers. An IP network is implemented in Internet networks, local area networks (LAN) and enterprise networks. All hosts or network nodes must be configured with the TCP/IP suite and must have an IP address. 5

6 Internetwork Communication Internetwork TCP/IP Host Company A Unique addressing allows communication between end stations Path choice is based on location Location is represented by an address Host Company B 6

7 Why IP Address Is Needed? 7

8 Addresses in the TCP/IP Protocol Suite 8

9 IP addressing Why? To communicate, systems require some methods for uniquely identifying sender and recipient. IP Addressing is one such method. 9

10 IP Encapsulation Encapsulation takes data from one layer and adds a header or trailer so that other layer can understand it. Layer 4 data IP Header IP protocol takes data Segments from Transport Layer. IP adds its own header information IP header contains information to deliver the packet like IP address etc. 10

11 IPv4 IP Version 4 is Traditional Addressing Scheme It is a 32 Bit Address The address space of IPv4 is 2 32 or 4,29,49,67,296 Unique Addresses 11

12 How Does IPv4 Work 12

13 IP Addressing To Bits Network Host Bits 0 to Bits 8 Bits 8 Bits 0 to to to

14 IP Addressing xxx.xxx.xxx.xxx Binary Representation Hexadecimal representation D E A 75951DEA 16 14

15 Classful Addressing Scheme IPv4 is a Classful addressing Scheme Facilitates larger number of network assignments. Number of Bits in network portion, determines class. Classes A B C D & E 15

16 Addressing Mode Unicast Addressing Mode: sent only to one destined host Broadcast Addressing Mode: Addressed to all hosts. HostID - all 1s Multicast Addressing Mode: Addressed to defined group. Class D e.g. online Games. 16

17 Network IP and Broadcast IP Network IP- Host bit all zeroes. Broadcast IP- Host bit all ones. Both addresses cannot be physically used. Given any IP address, a network IP and broadcast IP can be associated with it. 17

18 Class A Address 8 Bits 0 to 127 N 8 Bits 8 Bits 8 Bits H H H to # Bits network # host # (2 7-2) 126 (2 24-2)

19 Class B Address 8 Bits 128 to to # Bits N 8 Bits 8 Bits 8 Bits N H network # host # H (2 14-2) (2 16-2)

20 Class C Address 8 Bits 192 to 223 N 8 Bits 8 Bits 8 Bits N N H to # Bits network # host # (2 21-2) (2 8-2)

21 Special Classes of IP Class D: Multicast First Octet is 224 to 239 Leading 4 bits are Class E: Research First Octet is 240 to 254 Leading 4 bits are Loop-back: Functionality testing

22 Reserved IP Addresses IP address designates a default gateway. Represents "All Other Network Addresses". IP address is called the Broadcast address. 22

23 IP Address Class Class 1 st Octet Decimal Range 1 st Octet High Order Bits Network/ Host ID N=Network H=Host Default Subnet Mask Number of Networks Hosts per Network (Usable Addresses) A 1 126* 0 N.H.H.H B N.N.H.H C N.N.N.H (2 7 2) 16,382 (2 14 2) 2,097,150 (2 21 2) 16,777,214 (2 24 2) 65,534 (2 16 2) 254 (2 8 2) D Reserved for Multicasting E Experimental; used for research 23

24 Private IP Addresses When Nodes are not connected to the Internet they can use addresses in the private ranges to conserve IP Addresses and Security. Class Private Networks Start address Private Network Finish Address A B C

25 NAT Network Address Translation allows mapping of private addresses to public addresses and vice-versa. NAT is like Receptionist transferring call from Public telephone to Intercom 25

26 Subnet Mask Move to classless addresses with IP address and subnet mask. 26

27 Subnets More number of networks with the same address space. Using subnet Mask we can Effectively divide a network into subnets. 27

28 Know your IP Configuration ipconfig /all 28

29 Static & Dynamic IP 29

30 IPv6 Addresses IPv4 is running out of addresses. IPv6 Addresses are 128 bit long , or around addresses. 8 Groups of 4 hexadecimal digits. 2001:0db8:85a3:0000:0000:8a2e:0370:

31 Ports To send a letter Apart from Building Name We also have to specify Flat No i.e. the door Ports are Logical Doors Serves as communication endpoints. It is 16 Bit Number Ports Port No. with IP address forms Socket 31

32 Ports Well known port numbers are assigned by Internet Corporation for Assigned Names and Numbers (ICANN) Well Known Ports Registered Ports Private Ports

33 Some Well Known Ports In Windows 7 Computer >C:>Windows>System32>drivers>etc. FTP 20 Telnet 23 SMTP 25 HTTP 80 33

34 Display network connections & ports netstat -n 34

35 Domain Name System DNS is a hierarchical, distributed database That contains mappings of DNS domain names to various types of data, such as Internet Protocol (IP) addresses 35

36 Anatomy of a URL ( Uniform Resource Locator) http is the protocol is the server windows/ is the path default.asp is the filename 36

37 gtld Generic Top Level Domain maintained by Internet Assigned Numbers Authority (IANA).aero.info.net.asia.int.org.biz.jobs.pro.com.mil.tel.coop.mobi.travel.edu.museum.xxx.gov.name Country 37

38 What s the IP address of This is a list of the org name servers. Ask them. root server.net The DNS Process This is a list of the icai.org servers. Ask them local.name-server.net What s the IP address of This is a the IP address of What s the IP address of gtldserver.net This is a the IP address of Icai-server.net What s the IP address of 38

39 Network Services Applications running at the network - application layer and above providing data storage, manipulation, presentation, communication Capabilities Implemented using a client-server or peer-to-peer architecture Services like DNS, DHCP Common services on local area networks like printer, E Mail 39

40 On Demand Computing Model of technology and computing Resources are provided on an as-needed and when-needed basis Computing resources such as storage capacity, Bandwidth, computational speed and software applications Made available to users as and when needed Enterprise Driven or On-Demand vendor Benefits pay only for the computing resources utilised Biggest concerns about ODC are security and privacy 40

41 Public Global Internet Infrastructure POP DSL Router Logical ISP Network Point of Presence ISP Network access Point NAP Fibre Optic Cables 155 Mbps to Gbps. Edge Router NAP POP POP 41

42 Quality of Network Service Internet is being used for many real time services Achieve customer satisfaction thru Quality of service Voice over IP, IP TV, Online Games, video-on-demand Internet banking Goal of QoS is to provide guarantees on the ability of a network to deliver predictable results. 42

43 Category of QOS Best Effort Basis Services No guarantee on delivery, throughput or delivery. This is the least priority traffic. Differentiated Service Traffic is differentiated as per performance requirements. Queuing strategies depends on priority Guaranteed Service From Users Perspective Services like VoIP and Video etc. top priority in transmission at a guaranteed speed. Internet banking Organization s and access to intranet internet browsing for internal users Guaranteed services. Differentiated services Best effort basis. 43

44 The IP Networks We have learnt about IP Networks Network Services On-demand Computing Factors Impacting Quality of Network Services 44

45 References Ron Gilster, Jeff Bienvenu, and Kevin Ulstad, CCNA for Dummies, IDG Books Worldwide, Inc. Mark A. Sportack, IP Addressing Fundamentals, Cisco Press 45

46 The IP Networks Thank You 46