What Is TCP/IP?

1. What Is TCP/IP?  • A large collection of networking protocols and services • The Transmission Control Protocol (TCP) handles reliable delivery for messages of arbitrary size, and defines a robust delivery mechanism for all kinds of data across a network • The Internet Protocol (IP) manages the routing of network transmissions from sender to receiver, along with issues related to network and computer addresses, and much more

2. Origins of TCP/IP • In 1969, the Advanced Research Projects Agency (ARPA), a branch of the United States Department of Defense (DoD), funded an academic research project for a special type of long-haul network with following objectives: • A desire to withstand a potential nuclear strike • A desire to permit different kinds of computer systems to easily communicate with one another • A need to interconnect systems across long distances • A packet-switched network, which is known as ARPANET, was built as a result of this project

3. IP Addressing • An IP address is a numeric identifier assigned to each machine on an IP network • IP address consist of 32 bits divided in to four sections (octets) • Usually depicted in one of three formats Decimal: 172.16.30.56 Binary: 10101100.00010000.00011110.00111000 Hexadecimal: AC 10 1E 38 • 232=4,294,967,296 possible number of addresses

4. Binary-to-Decimal Conversion Decimal Binary 120,321 101010 100×1= 1 101×2= 20 102×3= 300 103×0= 0 104×2= 20,000 + 105×1= 100,000 120,321 20×0= 0 21×1= 2 22×0= 0 23×1= 8 24×0= 16 + 25×1= 32 58 00000000= 0 10000000= 128 11000000= 192 11100000= 224 11110000= 240 11111000= 248 11111100= 252 11111110= 254 11111111= 255 20 = 0 21 = 2 22 = 4 23 = 8 24 = 16 25 = 32 26 = 64 27 = 128 28 = 256 Practice: Write IP address 10101100.00010001.00011000. 01010011 in decimal numbers.

5. Hierarchical Addressing • IP addressing is a hierarchical addressing • Hierarchical addressing makes sure efficient routing IP Pool Network Network Network Host Host Sub-net Sub-net Host Host

6. Network Address Ranges • Class A: the first bit of the first byte is always 0 (0xxxxxxx.) • Range • minimum 00000000. =0. • maximum 01111111. =127. • Format: network.node.node.node • Valid Network Addressing • 00000000.- is reserved for the default route for the network • 01111111.- is reserved for diagnostics • What is the maximum usable number of Class A network addresses? • Valid Host Addressing • -.0.0.0 is reserved for network address • -.255.255.255 is the broadcast address • What is the maximum usable number of Class A node (hosts) addresses?

7. Class B: The first byte is always 1 and the second byte is always 0 (10xxxxxx.) • Range • minimum 10000000.=128. • maximum 10111111.=191. • Format: network.network.node.node • Valid Host Addressing • -.-.0.0 is reserved for the network address • -.-.255.255 is the broadcast address • What is the maximum usable number of Class B node (hosts) addresses? • Class C: The first two bytes are always 1 (11xxxxxx) • Range • 11000000. = 192 • 11111111. = 223 • Format: network.network.network.node • Valid Host Addressing • -.-.-.0 is reserved for the network address • -.-.-.255 is the broadcast address • What is the maximum usable number of Class A node (hosts) addresses? • Class D: Reserved for multicast address (224-239) • Class E : Reserved for scientific purposes (240-255)

8. Subnetting • Breaking a large network into smaller networks • Benefits • Reduced traffic • Optimize network performance • Simplified management • Helps expending the network • To create subnetworks, bits from the host portion is revered to define the subnet address

9. Subnet Mask • 32-bit information to distinguish the network and host portions of the IP address

10. Subnetting Class C Last two digits are reserved for hosts Subnetting formulas x=number of masked bits Number of subnets on the network= 2x-2 Number of hosts per subnet=28-x-2

11. Example Network address=192.168.10.0 Subnet mask=255.255.255.192 01 000000=64 The network (192.168.10.64) 01 000001=65 The first valid host (192.168.10.65) 01 111110=126 The last valid host (192.168.10.126) 01 111111=127 The broadcast (192.168.10.127) Subnet 64 01xxxxxx 10 000000=128 The network (192.168.10.128) 10 000001=129 The first valid host (192.168.10.129) 10 111110=190 The last valid host (192.168.10.190) 10 111111=191 The broadcast (192.168.10.191) Subnet 128 10xxxxxx

12. Fast Way: Subnetting a Class C • Find the network addresses Subnet mask=192 256-192=64 based number and .64 is the first subnet 64+64=128 the second subnet .128 is the second subnet 128+64=192 (subnetmask. Stop) 2. Find the broadcast address for each subnet The number immediately preceding next subnet number 3. Find the valid host addresses Valid host are numbered between the subnets.

13. Example Network address=192.168.10.0 Subnet mask=255.255.255.224 The numbers of subnets and host? Network and Broadcast Addresses for each subnet? Valid Host Addresses?

14. Subnetting Class B Number of subnets on the network= 2x-2 Number of hosts per subnet=216-x-2

15. Example Network address=180.168.0.0 Subnet mask=255.255.192.0 01000000.000000=64.0 The network (180.168. 64.0) 01000000.000001=64.1 The first valid host (180.64.1) 01111111.111110=127.254 The last valid host (180.168.127.254) 01111111.111111=127.255 The broadcast (180.168.127.255) Subnet 64 01xxxxxx.xxxxxxxx 10000000.000000=128.0 The network (180.168. 128.0) 10000000.000001=128.1 The first valid host (180.128.1) 10111111.111110=191.254 The last valid host (180.168.191.254) 10111111.111111=191.255 The broadcast (180.168.191.255) Subnet 128 10xxxxxx.xxxxxxx

16. Example • Network Address=172.16.0.0 • Subnetmask=255.255.240.0 The numbers of subnets and host? Network and Broadcast Addresses for each subnet? Valid Host Addresses?

17. Example • Network Address=172.16.0.0 • Subnetmask=255.255.255.192 (/26) The numbers of subnets and host? Network and Broadcast Addresses for each subnet? Valid Host Addresses?