Subnet Calculator

Calculate network addresses, subnet masks, and host ranges for IP networks

Understanding Subnetting

Subnetting allows you to divide a large network into smaller, more manageable subnetworks. This calculator helps you determine network addresses, host ranges, and subnet masks based on CIDR notation.

Key Concepts

  • Network Address:The first address in a subnet block
  • Broadcast Address:The last address in a subnet block
  • CIDR Notation:Represents network size (e.g., /24)
  • Subnet Mask:Defines network and host portions

Common Subnet Masks

/24255.255.255.0256 addresses
/25255.255.255.128128 addresses
/26255.255.255.19264 addresses
/27255.255.255.22432 addresses
/28255.255.255.24016 addresses
/29255.255.255.2488 addresses

Subnetting Best Practices

Planning

  • • Determine future growth needs
  • • Account for network devices
  • • Plan for scalability
  • • Document all subnets

Implementation

  • • Use efficient subnet sizes
  • • Implement security zones
  • • Configure proper routing
  • • Test connectivity

Management

  • • Monitor network usage
  • • Update documentation
  • • Review security policies
  • • Plan for IPv6 transition