Seven Second Subnetting Process

Overview

• Focus on quick subnetting techniques for exams.
• Minimal math involved (only addition and subtraction).
• Emphasizes creating charts to streamline the process.

Creating Charts

• Use tables for subnetting references.
• Important for both testing centers and online exams.
• Charts provide values for subnet masks, networks, and host addresses.

Comparison with Magic Number Method

• Both methods share similar processes.
• Customize either method to suit personal preferences.

Key Elements of Seven Second Subnetting

1. Convert IP Address and Subnet Mask to Decimal
   • Important for understanding subnetting boundaries.
2. Calculate Network Address
   • Use the chart to determine values based on subnet mask.
3. Calculate Broadcast Address
   • Similar process as network address; use chart to find ranges.
4. Calculate Usable IP Addresses
   • First usable IP: Network Address + 1
   • Last usable IP: Broadcast Address - 1

Example Calculation

Example IP: 165.245.12.88/24

• Convert: 255.255.255.0
• Network Address: 165.245.12.0
• Broadcast Address: 165.245.12.255
• First Usable IP: 165.245.12.1
• Last Usable IP: 165.245.12.254

Example IP: 165.245.12.88/26

• Convert: 255.255.255.192
• Network Address: 165.245.12.64
• Broadcast Address: 165.245.12.127
• First Usable IP: 165.245.12.65
• Last Usable IP: 165.245.12.126

Example IP: 165.245.12.88/20

• Convert: 255.255.240.0
• Network Address: 165.245.0.0
• Broadcast Address: 165.245.15.255
• First Usable IP: 165.245.0.1
• Last Usable IP: 165.245.15.254

Additional Examples

• IP: 18.172.200.77/11

  • Convert: 255.224.0.0
  • Network Address: 18.160.0.0
  • Broadcast Address: 18.191.255.255

• IP: 18.172.200.77/17

  • Convert: 255.255.128.0
  • Network Address: 18.172.128.0
  • Broadcast Address: 18.172.255.255

Tips for Success

• Practice creating charts before exams.
• Use a dry erase marker for better readability during tests.
• Find a subnetting method that feels comfortable and efficient for you.