1. Introduction

1.2. 2. Internet Layer

Function: Manages logical addressing and routing of data packets across multiple networks to reach their destination, equivalent to the OSI model’s Network layer.

Key Responsibilities:

Assigns logical addresses (e.g., IP addresses) to identify devices.

Routes packets through interconnected networks to find the best path.

Handles packet fragmentation and reassembly for efficient transmission.

Supports inter-network communication, enabling the internet’s global reach.

Examples:

Protocols: Internet Protocol (IP - IPv4, IPv6), Internet Control Message Protocol (ICMP), IPsec.

Devices: Routers, Layer 3 switches.

Routing Protocols: OSPF (Open Shortest Path First), BGP (Border Gateway Protocol), RIP.

Example: IP address (e.g., 192.168.1.1 or 2001:db8::1).

Analogy: The Internet layer is like a GPS system, directing packets across cities (networks) using unique addresses to reach their destination.