IPv6 Subnet Calculator
Calculate IPv6 subnet information, expand and compress addresses, detect address types, and divide networks. Essential tool for network administrators working with IPv6.
Common IPv6 Prefix Sizes
| Prefix | Description | Typical Use |
|---|---|---|
| /128 | Single host (loopback) | Host route |
| /127 | Point-to-point link | Inter-router links |
| /64 | Standard subnet | LAN, SLAAC required |
| /56 | Small site | Residential (256 /64s) |
| /48 | Site allocation | Enterprise (65,536 /64s) |
| /32 | ISP allocation | Service provider |
| /16 | RIR allocation | Regional registry |
| /12 | Large allocation | Major registry block |
Special IPv6 Addresses
| Address | Name | Description |
|---|---|---|
| ::/128 | Unspecified | No address assigned |
| ::1/128 | Loopback | Localhost |
| fe80::/10 | Link-Local | Local network only |
| fc00::/7 | Unique Local | Private networks |
| ff00::/8 | Multicast | One-to-many |
| 2000::/3 | Global Unicast | Internet routable |
| 2001:db8::/32 | Documentation | Examples only |
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Master IPv6 Addressing and Subnetting
IPv6 is the next-generation Internet Protocol with 128-bit addresses providing virtually unlimited address space. Our IPv6 Subnet Calculator helps you analyze addresses, calculate subnets, and understand the structure of IPv6 networks.
What Is IPv6?
IPv6 uses 128-bit addresses represented as eight groups of four hexadecimal digits (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). The vast address space (2^128 addresses) eliminates the need for NAT and enables direct connectivity for all devices.
IPv6 Address Space
Total Addresses = 2^128 approximately 340 undecillion addressesWhy Use This Calculator?
Address Analysis
Identify address types (global unicast, link-local, multicast, etc.) instantly.
Format Conversion
Expand compressed addresses or compress expanded ones following RFC standards.
Subnet Planning
Calculate subnet ranges and divide networks into smaller subnets.
Binary Visualization
View the full 128-bit binary representation of any IPv6 address.
How to Use
Common Applications
Network Design
Plan IPv6 address allocation for enterprise networks and data centers.
Troubleshooting
Identify address types and verify subnet configurations.
Education
Learn IPv6 addressing concepts with visual binary representations.
Cloud Infrastructure
Configure IPv6 subnets for VPCs in AWS, Azure, or GCP.
Frequently Asked Questions
The standard subnet size is /64, which allocates 64 bits for the network prefix and 64 bits for the interface identifier. This is required for SLAAC (Stateless Address Autoconfiguration) to work properly.