# IP Subnet Calculator by Franco (Systematic)
> https://www.calcip.com/

An essential toolset for network engineers and CCNA students, developed by Franco Tsang at Systematic Computer Education Centre. This platform provides precise IP addressing, subnetting calculations, and educational resources for Cisco certification candidates.

## Developer & Organization
- **Developer**: Franco Tsang (CCIE #19772). 
  - Holds triple CCIE certifications (Routing & Switching, Security, Service Provider).
  - Over 20 years of experience in teaching Cisco CCNA/CCNP and IT security.
  - Security Consultant for major Hong Kong forums (Discuss.com.hk, Uwants.com).
- **Organization**: Systematic Computer Education Centre (https://www.systematic.com.hk/). 
  - A leading IT training center in Hong Kong (established since 1993) providing professional certification courses in AI, Cloud, Networking, and Security.

## Core Capabilities
- **IPv4 Subnet Calculator**: Calculates network address, broadcast address, usable host range, and wildcard mask from IP and CIDR/Subnet Mask.
- **Route Summarization**: Aggregates multiple IP routes into a single summary route to minimize routing tables.
- **IPv6 Calculator**: Handles IPv6 address compression, expansion, and prefix calculations.
- **EUI-64 Generator**: Converts a 48-bit MAC address into a 64-bit Interface Identifier for IPv6 auto-configuration.
- **CCNA Exam Prep**: Provides practice questions, concepts, and tips for the Cisco Certified Network Associate (200-301) certification.

## Technical Reference & Logic
- **Subnetting**: Uses standard VLSM (Variable Length Subnet Mask) logic.
- **EUI-64 Process**: 
    1. Split 48-bit MAC (e.g., 00:11:22:33:44:55).
    2. Insert `FF:FE` in the middle (0011:22FF:FE33:4455).
    3. Flip the 7th bit (Universal/Local bit) of the first byte.
- **Summarization**: Finds the longest common bit prefix among a list of IP addresses.

## Tools & Links
- [Subnet Calculator](https://www.calcip.com/) - Main tool for IPv4/IPv6 subnetting.
- [IPv6 EUI-64](https://www.calcip.com/eui-64/) - Dedicated EUI-64 conversion tool.
- [CCNA Questions](https://www.calcip.com/ccna-q) - Practice questions and exam tips.
- [CCNA Course Details](https://www.systematic.com.hk/ccna-fast-course-training.htm) - Official training at Systematic.
- [Franco's Course List](https://www.systematic.com.hk/course_Franco.htm) - Full range of courses taught by the developer.

## API & Integration (Planned)
- Support for MCP (Model Context Protocol) is under consideration for direct AI tool calling.