computer networking basics for higher studies

Computer networking

1. Computer Networks Lecture - 05 By Rajith Karunarathne (B.Sc.( sp )-UWU SL, M.Sc.-RTU Latvia)

2. Introduction to IPv4 IPv4 stands for Internet Protocol version 4. It is widely used to identify devices on a network. IPv4 uses a 32-bit address scheme, allowing for 4.3 billion unique addresses.

3. Structure of IPv4 Address IPv4 addresses are written in dotted decimal notation, e.g., 192.168.1.1. Consists of four octets (each 8 bits), separated by periods. Example: 11000000.10101000.00000001.00000001 (binary representation of 192.168.1.1).

4. Classes of IPv4 Addressing IPv4 addresses are divided into five classes: Class A (1.0.0.0 – 126.255.255.255) – Large networks. Class B (128.0.0.0 – 191.255.255.255) – Medium-sized networks. Class C (192.0.0.0 – 223.255.255.255) – Small networks. Class D (224.0.0.0 – 239.255.255.255) – Multicasting. Class E (240.0.0.0 – 255.255.255.255) – Experimental use.

5. Types of IPv4 Addresses Public IP Address – Assigned by ISPs, globally routable. Private IP Address – Used within local networks (e.g., 192.168.x.x, 10.x.x.x). Loopback Address – 127.0.0.1, used for testing. Broadcast Address – Used to communicate with all devices on a network.

6. Activity - 01 A device has the IP address of 140.100.96.10. Represent the above IP address in Binary form. ii. What is the class that the above IP address belongs. iii. Write the Network address that the above IP address belongs. iv. What is the subnet mask of the above given IP address. V. What is the Broadcast Address vi. Calculate the Number of Hosts

7. Subnetting in IPv4 Subnetting divides a large network into smaller sub-networks. Helps improve security, performance, and manageability. Uses a Subnet Mask (e.g., 255.255.255.0) to differentiate network and host portions.

8. Activity - 02 A device in the network has an IPv4 address of 194.248.48.10/26. i How many bits were used for the subnet? ii.How many subnets that could be made in this network? iii. What is the Network address? iv. What is the subnet mask?

9. Activity - 03 A device in the network has an IPv4 address of 194.248.48.10/24, 194.248.48.10/25, 194.248.48.10/26 and 194.248.48.10/27. i How many bits were used for the subnet? ii.How many subnets that could be made in this network? iii. What is the Network address? iv. What is the subnet mask?

10. Limitations of IPv4 Limited address space (4.3 billion addresses, many already allocated). Security vulnerabilities. No built-in support for encryption or authentication. Need for Network Address Translation (NAT) to extend address usage.

11. Transition to IPv6 Due to IPv4 limitations, IPv6 was introduced. IPv6 uses a 128-bit address, significantly increasing available addresses. IPv4 and IPv6 coexist, and transition mechanisms include Dual Stack, Tunneling, and NAT64.

12. Summary IPv4 is the backbone of the modern internet but has limitations. Uses a 32-bit address format, categorized into different classes. Subnetting helps optimize network performance. IPv6 is the future, addressing IPv4 limitations.

13. Q&A Any questions?