Private Network Vs Public Network

 Private Network

Definition: A private network is a network that is restricted to a specific group of users or devices. It is not accessible from the public internet and is typically used for internal communication and resource sharing within an organization or home.

A private network is a network used within a specific organization, home, or other closed environment. It is not directly accessible from the public internet. It is designed to allow secure communication and resource sharing among devices that are part of the network.

Characteristics:

• Accessibility: Accessible only by authorized users within the network. It is isolated from external networks.
• Security: Generally more secure because it is not exposed to the broader internet. Security measures like firewalls, VLANs, and access controls are commonly used.
• IP Addressing: Uses private IP address ranges defined by standards (e.g., RFC 1918) that are not routable over the internet.

Private IP Address Ranges:

• 10.0.0.0 to 10.255.255.255
• 172.16.0.0 to 172.31.255.255
• 192.168.0.0 to 192.168.255.255

Examples:

1. Home Network:

   • Devices: Computers, smartphones, tablets, and printers within a home.
   • Router: The home router assigns private IP addresses to devices in the range 192.168.1.x.
   • Use: Devices can communicate with each other, share files, and access the internet through the router, which uses Network Address Translation (NAT) to handle public IP traffic.

2. Corporate LAN (Local Area Network):

   • Devices: Office computers, servers, printers, and network storage.
   • Network Setup: The corporate LAN might use private IP ranges like 10.1.0.0/16 and 192.168.10.0/24 for internal devices.
   • Use: Employees can access internal applications, file servers, and printers. The network is secured and managed by IT staff.

Public Network

Definition: A public network is a network that is accessible to anyone on the internet. It includes the global network infrastructure and services that are available to the general public.

Characteristics:

• Accessibility: Accessible by anyone who has the necessary permissions or credentials. Public IP addresses are routable over the internet.
• Security: Generally less secure due to its openness and exposure to potential threats. Security measures like encryption, firewalls, and intrusion detection are used to protect data and services.
• IP Addressing: Uses public IP addresses that are unique and routable across the internet.

Examples:

1. Internet:

   • Devices: Web servers, websites, online services, and content delivery networks.
   • IP Addresses: Public IP addresses assigned to these servers are routable and accessible from anywhere on the internet.
   • Use: Users can browse websites, use online applications, and communicate globally.

2. Public Wi-Fi Network:

• Devices: Wi-Fi hotspots in cafes, airports, and public places.
• Access: Anyone within range can connect to the public Wi-Fi network, usually with minimal or no authentication.
• Security: Public Wi-Fi networks are often less secure, so it’s important to use encryption (like VPNs) to protect sensitive information.

Situation:

When you connect to the internet through a router, you are typically using both a private network and a public network. Here’s a breakdown of how each network plays a role in this setup:

1. Private Network

Definition in Context:

• The private network is the local network within your home or office that is managed by your router. This is the network to which your devices (e.g., computers, smartphones, printers) connect.

Characteristics:

• Local IP Addresses: Devices on this network use private IP addresses (e.g., 192.168.1.x).
• Internal Communication: Devices can communicate with each other and share resources (like files or printers) within this network.
• Isolation: This network is isolated from the broader internet, providing a level of security.

Example:

• Home Network: Your router assigns private IP addresses to devices in your home. For example, your computer might have an IP address like 192.168.1.10 on this network. This private network allows you to manage and control traffic within your home.

2. Public Network

Definition in Context:

• The public network is the broader internet that connects your private network to the outside world. It is what allows your devices to access websites, online services, and other resources not within your local network.

Characteristics:

• Public IP Address: Your router typically has a single public IP address (e.g., 203.0.113.5) assigned by your Internet Service Provider (ISP). This public IP address is used to communicate with the broader internet.
• Global Accessibility: This address is used to route traffic to and from the internet. It’s accessible globally and allows you to reach websites and online services.
• NAT (Network Address Translation): The router uses NAT to manage and translate between the private IP addresses of your devices and the public IP address used on the internet.

Example:

• Internet Access: When you browse a website, your request is sent from your private network through the router's public IP address to the internet. The website responds to the public IP address, and the router then forwards the response back to your specific device on the private network.

Workflow Example

1. Connecting to the Internet:

   • Device: Your laptop connects to the router via Wi-Fi or Ethernet.
   • Router: The router assigns a private IP address to your laptop (e.g., 192.168.1.10) and manages the connection to the internet.

2. Accessing a Website:

   • Request: Your laptop requests a webpage from a website.
   • Private to Public: The router translates the private IP address to the router's public IP address and sends the request to the internet.
   • Response: The website’s server responds to the public IP address, and the router forwards the response to your laptop.