Binary Rules

FIRST CONVERT ADD INTO BINARY

1. To workout the Network/Subnet Address

• Fill the host portion of Address with Binary 0's (then convert it to Decimal)

  2. To workout the First Host Address in a Subnet

• Fill the host portion of the Address with Binary 0's except for the last bit which is set to Binary 1 (then convert it to Decimal)

  3. To workout the Last Host Address in a Subnet

• Fill the host portion of the Address with Binary 1's except for the last bit which is set to 0. (then convert it to Decimal)

  4. To workout the Broadcast Address

• Fill the host portion of the Addresses with Binary 0's except for the last bit which is set to 1.(then convert it to Decimal)

Why only work on the Host Portion?

• Because mask indicates Number of bits on the Network Side (already reserved)

• /24 = 255.255.255.0

• Hence we only work on the Host side

Practical Example:

• Subnetting Binary Method Example 1

• Subnetting Binary Method Example 2

• Subnetting Binary Method Example 3

Reference:

• https://www.udemy.com/course/cisco-ccent-icnd1-100-105-complete-course-sims-and-gns3/learn/lecture/6087496#overview