Understanding Binary Weight and Subnetting

In networking, it's essential to understand binary weights and how they relate to subnetting. Here's a simple binary weight table:

128 | 64 | 32 |16 | 8 | 4 | 2 | 1

Each value represents a power of 2, which is fundamental in binary calculations. Let's break down what each number means:

• 128: 2^7
• 64: 2^6
• 32: 2^5
• 16: 2^4
• 8: 2^3
• 4: 2^2
• 2: 2^1
• 1: 2^0

How It Applies to Subnetting

Subnetting involves dividing a network into smaller pieces. The binary weight table helps understand how subnet masks work. For example, consider a Class C network with a default subnet mask of 255.255.255.0. In binary, this is 11111111.11111111.11111111.00000000.

Using our table:

• The first three octets (255) are for the network.
• The last octet (0) is for the host.

Example: Calculating Subnet Ranges

Let's say you want to create subnets within a /26 network:

128 | 64 | 32 | 16 | 8 | 4 | 2 | 1

1 | 1 | 0 | 0 | 0 | 0 | 0 | 0

Here, the first two bits are used for the network, leaving the rest for hosts. This gives a subnet increment of 64 (from the second column). So, your subnets will be:

• 0-63
• 64-127
• and so on.

Why It Matters

Understanding this table makes network design and management easier. It helps you calculate subnet masks and ranges quickly, which is crucial for creating efficient networks.