Here's a concise summary of the video about IP addressing version 4 and subnets:
The video starts with an introduction to IP addressing version 4, which is a 32-bit number divided into four bytes, with each byte represented in decimal notation and separated by dots.
The instructor explains that an IP address consists of a network identifier and a host identifier, and that the division between the two can vary. In the old classful addressing system, IP addresses were assigned to a specific class, which determined how many bits belonged to the network and how many to the host.
The instructor discusses the three main classes of addresses: A, B, and C. Class A addresses have 8 network bits and 24 host bits, Class B addresses have 16 network bits and 16 host bits, and Class C addresses have 24 network bits and 8 host bits.
The instructor also explains how to determine the class of an IP address by looking at the first byte and using a table to determine the range of values for each class.
The video then discusses network masks, which are used to determine the network and host bits in an IP address. The instructor explains that network masks can be represented in dotted decimal notation or as a prefix.
The instructor also introduces the concept of subnets, which are divisions of a larger network. To create subnets, bits are borrowed from the host portion and reassigned to the network portion. The instructor provides examples of how to create subnets and calculate the number of available hosts and subnets.
Finally, the instructor explains how to calculate the network address, broadcast address, and available hosts for a given subnet. The video concludes with a summary of the key concepts and a musical ending.
Here are the key facts extracted from the text:
1. An IP address is a 32-bit binary number.
2. The 32-bit IP address is divided into 4 bytes, with each byte consisting of 8 bits.
3. Each byte of the IP address is converted into its decimal notation, separated by dots (e.g., 131.108.122.204).
4. This notation is known as the dotted decimal notation.
5. An IP address consists of a network identifier and a host identifier.
6. In some cases, the division between network and host identifiers is in half, but it can vary.
7. The class of an IP address is determined by the first 8 bits (Class A), 16 bits (Class B), or 24 bits (Class C).
8. Class A addresses have 8 network bits and 24 host bits.
9. Class B addresses have 16 network bits and 16 host bits.
10. Class C addresses have 24 network bits and 8 host bits.
11. The class of an IP address can be determined by the first value (object) in the dotted decimal notation.
12. The class scheme only applies to IP protocol version 4.
13. A network prefix represents the number of bits that belong to the network.
14. A subnet mask can be used to divide a larger network into smaller subnets.
15. To create subnets, bits are borrowed from the host portion and reassigned to the network portion.
16. The subnet mask explicitly establishes which bits belong to the network and subnet.
17. Changing the subnet mask can help to save or not waste address space.
18. The network address is always expressed in dotted decimal notation, with the host portion being zero.
19. A subnet is a division of a larger network into smaller networks.
20. The number of subnets that can be created depends on the number of bits borrowed from the host portion.