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Subnet vs Supernet (CIDR)

What?

  • Subnet:
  • Subnetting is like dividing a big office building into smaller departments. Each department has its own space and resources, making it easier to manage and control.
  • Supernet (CIDR):
  • Supernetting, or CIDR, is like combining multiple office buildings into one big complex. It simplifies management by treating them as one entity, reducing administrative overhead.

Why?

  • Subnet:
  • It helps organize and secure the network, improves performance, and simplifies management by breaking it into manageable parts.
  • Supernet (CIDR):
  • It reduces routing table size, optimizes IP address usage, and streamlines network management for larger-scale networks.

How?

  • Imagine you're managing a company network with three departments: Sales, Marketing & IT.
  • Each department requires its own subnet for better organization and security.
  • Sales Department:
    • IP address range: 192.168.1.0/24
    • Example IP addresses: 192.168.1.1, 192.168.1.2, etc.
  • Marketing Department:
    • IP address range: 192.168.2.0/24
    • Example IP addresses: 192.168.2.1, 192.168.2.2, etc.
  • IT Department:
    • IP address range: 192.168.3.0/24
    • Example IP addresses: 192.168.3.1, 192.168.3.2, etc.

With subnetting, each department has its own distinct IP address range, allowing for efficient management and isolation of network traffic.

Supernetting (CIDR for Branch Offices): Now, consider the company's branch offices, each with its own IP address range: - Branch Office 1: - IP address range: 10.0.0.0/24 - Branch Office 2: - IP address range: 10.0.1.0/24 - Branch Office 3: - IP address range: 10.0.2.0/24

  • Instead of managing each branch office network separately, you can aggregate these networks into one larger network using CIDR notation:
  • Branch Offices Supernet:
  • Aggregate IP address ranges: 10.0.0.0/22
  • Example IP addresses: 10.0.0.1, 10.0.1.2, 10.0.2.3, etc.

With supernetting, you combine multiple smaller networks into one larger network, simplifying routing and management.

In summary, subnetting is used to divide a network into smaller, more manageable segments (like departments in a company), while supernetting (CIDR) is used to combine multiple smaller networks into one larger network (like branch offices in a company). Both techniques optimize network management and routing but serve different purposes.