The Internet is made up of many networks from different Internet Service Providers. These providers connect a large number of networks and data centres. There are two main categories of providers:
Backbone providers
Responsible for the main international cable routes
Local providers
Responsible for providing Internet endpoints to users
Each connected device is given a unique address called IPv4 or IPv6.
Domains can be used as aliases for human readable representation.
The OSI model is a standard for describing the operation of connections between two devices. It consists of 7 different layers, each with different responsibilities and functions.
1 - Physical Layer
Purpose: Transmits raw bits (0s and 1s) over the physical medium
Functions:
Defines physical characteristics like cables and frequencies
Purpose: Translates and formats data for the application layer.
Functions:
Converts data formats (e.g., from ASCII to Unicode).
Handles data encryption and compression.
Examples: SSL/TLS, JPEG, MPEG.
IP Assignment
There are several ways to assign an IP address to clients. The most common method is dynamic assignment via DHCP. Another option is to assign static IP addresses to clients.
IP addresses are assigned to network interfacees. This is why you can see multiple ip addresses in ip a or ipconfig.
