IPv6 Subnet Calculator
Calculate IPv6 subnet information with 128-bit addressing and modern network prefix notation.
Network Configuration
/64 - Standard subnet (single network segment)
Common IPv6 Networks
About IPv6 Subnetting
IPv6 subnetting uses 128-bit addresses and hierarchical prefix-based allocation to provide virtually unlimited address space. Unlike IPv4, IPv6 simplifies subnet planning with:
Massive Address Space
128-bit addressing provides 2^128 addresses - virtually unlimited for any network
Simplified Subnetting
Standard /64 subnets eliminate complex subnet calculations
Hierarchical Design
Provider-independent addressing with clear network hierarchy
No Broadcast Domain
Uses multicast instead of broadcast, improving network efficiency
IPv6 Address Structure
Global Unicast (2000::/3)
Internet-routable addresses for global connectivity
Link-Local (fe80::/10)
Local network communication, automatically configured
Unique Local (fc00::/7)
Private addresses for internal networks (like RFC 1918)
Multicast (ff00::/8)
One-to-many communication replacing broadcast
IPv6 Subnetting Best Practices
Standard /64 Subnets
Use /64 for all LAN segments to ensure SLAAC and privacy extensions work properly
Hierarchical Allocation
Plan address space hierarchically: /48 sites, /56 small sites, /64 subnets
Address Compression
Use :: notation to compress consecutive zero groups for readability
Documentation Prefix
Use 2001:db8::/32 for examples and documentation
IPv6 Planning Tip
IPv6's massive address space eliminates the need for complex subnetting. Focus on logical network hierarchy rather than conserving addresses. A single /64 subnet provides more addresses than the entire IPv4 internet.