TCP/IP Addressing & Subnetting

1. TCP/IPAddressing & Subnetting Unit objectives • Discuss TCP/IP addressing and determine the IP address class and default subnet mask • Discuss subnetting and special addressing • Discuss the installation and configuration of TCP/IP

2. Topic A • Topic A: IP addressing • Topic B: Subnetting and special addressing • TCP/IP installation and configuration

3. Addressing • Each networked system must be identified as unique • This is accomplished through the machine’s MACaddress • Each machine must also have a uniqueIP address

4. IPAddresses • Made up of a 32-bit address or four octet address • The three major IP address classes • Class A • Class B • Class C • There are also Class D and Class E addresses, used for multicasts (D) and for research (E), but these addresses are not used by any group or. individuals

5. Address conversion • An IP address is a 32-bit address, written as four octets or bytes, separated by periods. • For example: 195.143.67.2 • This way of representing an IP address is also known as “dotted decimal” notation

6. A sample of binary numbers

7. Binary-to-decimal conversion • To convert a binary number to a decimal number • Determine the decimal value for each of the bits • Add up the bit values

8. 11000000 11011010 10011101 00000011 Binary-to-decimal conversion

9. 1 1 0 0 0 0 0 0 128 64 32 16 8 4 2 1 128 64 0 0 0 0 0 0 Binary-to-decimal conversion • The middle row here is sometimes called a “binary tree – it runs from right to left, increasing by doubling in each subsequent spot – 1, 2, 4, 8, and so on. • The top row is the binary number, the middle row shows the value of each “1” in the top row. If there is a 1 in the top row, the corresponding value for that spot in the binary tree is brought down to the bottom row. The bottom row is just added to give you the decimal equivalent of the binary number. In this example, 1100 0000 = 128 + 64 = 192.

10. 1 1 0 1 1 0 1 0 128 64 32 16 8 4 2 1 128 64 0 16 8 0 2 0 Binary-to-decimal conversion Try this one ….

11. 1 0 0 1 1 1 0 1 128 64 32 16 8 4 2 1 128 0 0 16 8 4 0 1 Binary-to-decimal conversion

12. 0 0 0 0 0 0 1 1 128 64 32 16 8 4 2 1 0 0 0 0 0 0 2 1 Binary-to-decimal conversion

13. Decimal-to-binary conversion • To convert decimal into binary • Set up a table as shown • The fourth column provides bit values

14. IP Addressing - (Cisco PPt)

15. IP Addressing - (Cisco PPt)

16. IP Addressing - (Cisco PPt)

17. IP Addressing - (Cisco PPt)

18. IP Addressing - (Cisco PPt)

19. Activity A-1 page 10-5 Discussing IP addresses and conversions

20. The IP address classes • Five address classes are supported by TCP/IP: A, B, C,D, and E • Classes A, B, and C are assigned to the general user community • Class D addresses are reserved for multicasting • Class E addresses are reserved for experimental purposes

21. IP Addressing - (Cisco PPt) • MAC to IP address translation • IP classes • Internet Assigned Numbers Authority (IANA) • American Registry of Internet Numbers (ARIN) • Internet Corporation for Assigned Names and Numbers (ICANN) • Class A • Class B • Class C • Class D • Class E • Private IP ranges

22. The Class A network • The first octet defines the networkportion of the address • The last three octets are used for subnet masking and host addresses • A default subnet mask of 255.0.0.0 is assigned for a Class A network • Subnet masks? The book does get to this later; for now, it is another 32-bit number in 4 8-bit octet form, just like the IP address. The mask determines which part of the IP address represents the network, and which part the hosts on that network.

23. The Class B network • The first two octets are used for the network address • The last two octets are used for subnetting and host addresses • A default subnet mask of 255.255.0.0 is assigned for a Class B network • A Class B address is often used when setting up a moderate- to large-sized network

24. The Class C network • The first three octets are used for the network address • The last octet is used for subnetting and host addresses • A default mask of 255.255.255.0 is assigned to a Class C network

25. IPv6 • Addresses are 128 bits • They’re made up of eight 16-bit fields, allowing for a total of 296addresses • The fields are represented by 16-bit hexadecimal numbers • Each field can be from 0 to FFFF (65535 in decimal) (or 65,536 addresses)

26. Activity A-2 Page 10-8 Discussing IP addressing

27. Managing addresses • Some potential problems in implementing TCP/IP • Population size • Portability • End users • The (one of the) standard(s) that has emerged to assist in managing TCP/IP addresses is DHCP

28. DHCP: Dynamic Host Configuration Protocol • An open standard that is defined within RFC 2131, Dynamic Host Configuration Protocol • Microsoft was the first manufacturer to implement DHCP • Provides an automated means of managing host IP addresses

29. Other addressing methods • BootP - an earlier attempt to centralize configuration IP addresses. The address pool is static rather than in a dynamic pool, as with DHCP. Other differences in the following slides. • Static assignment – You can assign a specific address to a node; useful if you have a device that other devices must find – like a server or a printer, for example. • Self assignment (APIPA) – You get an APIPA address when your computer can’t find a DHCP server. You can still communicate with other PCs on your network, but you can never get to another network, like the internet. • The APIPA client keeps searching for a DHCP server until it finds one.

30. DHCPDynamic Host Configuration ProtocolFive slides from another Power Point …

31. Introducing DHCP DHCP clients listen on UDP port 67. DHCP servers listen on UDP port 68 Rick Graziani graziani@cabrillo.edu

32. BOOTP and DHCP differences There are two primary differences between DHCP and BOOTP: • DHCP defines mechanisms through which clients can be assigned an IP address for a finite lease period. • This lease period allows for reassignment of the IP address to another client later, or for the client to get another assignment, if the client moves to another subnet. • Clients may also renew leases and keep the same IP address. • DHCP provides the mechanism for a client to gather other IP configuration parameters, such as WINS and domain name. Rick Graziani graziani@cabrillo.edu

33. Major DHCP features Rick Graziani graziani@cabrillo.edu

34. DHCP Operation Remember :   ‘Dora’ - Acronym • Note on how DHCP requests are propagated: • Routers, by default, will not forward broadcast packets. • DHCP client messages use the destination IP address of 255.255.255.255 (all Nets Broadcast). • So DHCP clients will not be able to send requests to a DHCP server on a different subnet unless the DHCP/BootP Relay Agent is configured on the router. Rick Graziani graziani@cabrillo.edu

35. Activity A-3 Page 10-11 Discussing IP addressing methods

36. Topic B • Topic A: IP addressing • Topic B: Subnetting and special addressing • TCP/IP installation and configuration

37. Subnetting • Subnets • improve network performance and • available bandwidth and • reduce overall traffic levels

38. A sample subnet

39. Subnet masks • Are used to identify the network and host portions of the address • The network portion identifies where the host is located, and the host portion identifies the deviceconnected to that network

40. Creating a custom subnet mask • A custom subnet mask tells TCP/IP to consider some of the bits, which by default would identify a host, as part of the network address • When a network is divided into subnets, all members of that subnet will have the same network prefix • Routersdivide the networks and provide communication between them

41. Subnet Addressing - (Cisco PPt) • Default class subnet masks • Class A subnet mask is 255.0.0.0 11111111.00000000.00000000.00000000 • Class B subnet mask is 255.255.0.0 11111111.11111111.00000000.00000000 • Class C subnet mask is 255.255.255.0 11111111.11111111.11111111.00000000 • Boolean ANDing operation • Subnet addresses • Broadcast addresses

42. Broadcast Types - (Cisco PPt) • Flooded broadcasts • 255.255.255.255 • Directed broadcast • 129.30.255.255

43. Subdividing IP Classes - (Cisco PPt)

44. Subnet Masking - (Cisco PPt)

45. Subnet Masking - (Cisco PPt)

46. Subnet Masking - (Cisco PPt)

47. Learning To Subnet: (Cisco PPt)

48. Learning To Subnet - (Cisco PPt) • Breakdown of 255.255.255.244 subnet mask • 0 (binary 00000000) — unusable • 32 (binary 00100000) • 64 (binary 01000000) • 96 (binary 01100000) • 128 (binary 10000000) • 160 (binary 10100000) • 192 (binary 11000000) • 224 (binary 11100000) — unusable

49. Learning To Subnet - (Cisco PPt)

50. Learning To Subnet - (Cisco PPt)