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IPv6 Tools

Expand, compress, and normalize IPv6 addresses. Generate EUI-64 interface identifiers from MAC addresses.

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What It Does

The IPv6 Tools suite provides three modes: Expand converts shortened IPv6 addresses to their full 32-character form. Compress reduces expanded addresses to the shortest valid notation. EUI-64 generates an IPv6 interface identifier from a MAC address using the Modified EUI-64 algorithm.

How to Use It

  1. Navigate to IP Tools → IPv6 Tools from the top menu.
  2. Choose a mode: Expand, Compress, or EUI-64.
  3. For Expand/Compress: enter an IPv6 address and click the button.
  4. For EUI-64: enter a MAC address and optional prefix, then click Generate.
  5. View results including the expanded form, compressed form, binary, prefix, and interface ID.
  6. Use Copy All or Download .txt to export.

EUI-64 Process

The Modified EUI-64 algorithm converts a 48-bit MAC address to a 64-bit IPv6 interface identifier:

  1. Split the MAC into two halves (e.g., 00:1A:2B and 3C:4D:5E).
  2. Insert FF:FE in the middle.
  3. Flip the 7th bit (Universal/Local bit) of the first byte.
  4. Combine with a /64 prefix to form the full IPv6 address.

This is commonly used for IPv6 SLAAC (Stateless Address Autoconfiguration).

Use Cases

  • Troubleshooting: Expand compressed addresses to identify specific octets.
  • ACL/firewall rules: Normalize addresses for consistent configuration.
  • SLAAC debugging: Verify EUI-64 interface IDs match expected MAC-based addresses.
  • Documentation: Convert between forms for network documentation.
  • Certification prep: Practice IPv6 addressing for CCNA/CCNP exams.