Introduction

• IP addresses are hierarchical and consist of a network portion and a host portion.
• The network portion is the same for all devices in a network, while the host portion varies.
• This structure allows for efficient routing and address allocation.

IP Address Structure

• An IP address is 32 bits long, divided into network and host portions.
• IP addresses are written in dotted decimal notation (e.g., 128.208.2.151).

Network Prefix

• A network prefix represents a block of IP addresses assigned to a network.
• Prefixes are written in CIDR notation (e.g., 128.208.0.0/24 indicates 24 bits for the network ID).

Subnet Mask

• A subnet mask defines which part of an IP address belongs to the network.
• It consists of a sequence of 1s for the network portion and 0s for the host portion.
• Example: The subnet mask for 128.208.0.0/24 is 255.255.255.0.

Routing and Prefix Distribution

• Routers use prefix lengths to determine network boundaries.
• Routing protocols distribute prefixes to ensure correct packet forwarding.
• Prefixes are often referred to by length, such as “/16” (slash 16).

Reference Books

1. Kurose, J. F., & Ross, K. W. Computer Networking: A Top-Down Approach. Pearson.
2. Tanenbaum, A. S., & Wetherall, D. J. Computer Networks. Pearson.