IPv6 ULA Generator

Generate private, non-routable IPv6 Unique Local Addresses (ULA) under the `fd00::/8` prefix in accordance with RFC 4193 specifications. Computes pseudo-random 40-bit Global IDs and `/64` subnet prefixes.

Why Use This Tool?

• Private IPv6 Networks: Allocate private non-routable IPv6 subnets for local LANs, VPNs, and internal Kubernetes clusters without ISP assignment.
• RFC 4193 Compliance: Ensure your private IPv6 subnets follow official RFC 4193 pseudo-random Global ID rules to prevent subnet collision during mergers.
• Dual-Stack Internal Networks: Implement private IPv6 alongside RFC 1918 private IPv4 networks.

How to Use

1. Enter MAC Address or NTP Timestamp (or click "Generate Random ULA").
2. The tool computes the SHA-1 hash and extracts the 40-bit Global ID.
3. Copy your generated RFC 4193 `fd00::/48` prefix and sample `/64` subnets.

Real Working Example

Input:

MAC Address: 00:11:22:33:44:55 | Action: Generate RFC 4193 ULA

Output Result:

IPv6 ULA Prefix: fd3a:8b9c:4e12::/48
Sample /64 Subnet: fd3a:8b9c:4e12:0001::/64
Usable Host Range: fd3a:8b9c:4e12:1::1 to fd3a:8b9c:4e12:1:ffff:ffff:ffff:ffff

Important Technical Details & Standards

• RFC 4193 SHA-1 Hash Algorithm: Concatenates NTP timestamp + MAC address and takes 40 least significant bits of SHA-1 digest for Global ID.
• fd00::/8 Prefix Enforcement: Guarantees `L=1` bit setting per RFC 4193 standard.
• Local Memory Execution: Zero network overhead.

Related Networking & Security Tools

• IPv6 Subnet Calculator: Compute IPv6 subnets and ranges.
• IPv6 Expander & Compressor: Expand and compress IPv6.
• IPv4 Subnet Calculator: Calculate IPv4 subnets.