What is a routed IPv6 /64 and /56 subnet on a VPS?
A routed IPv6 /64 is a block of 18,446,744,073,709,551,616 IPv6 addresses (that’s 18 quintillion) routed directly to your VPS. An IPv6 /56 is 256 such blocks: 256 separate /64 subnets, each with 18 quintillion addresses. Every ColossusCloud VPS comes with one IPv6 address by default, and you can request a routed /64 or /56 for free through the Client Portal when you need more.
What “routed IPv6 /64” means in practice
When an IPv6 /64 (or /56) is “routed” to your VPS, all traffic destined for any address in that block gets sent to your server. Your VPS becomes the endpoint for the entire range. You decide what to do with the addresses: assign them to containers, virtual machines, services, or anything else on your server.
Different from getting a single IP. With a routed subnet, you control a whole block.
IPv6 /64 vs /56 at a glance
- IPv6 /64 subnet: 1 network segment, 18 quintillion addresses. The standard IPv6 subnet size. Enough for any single-network deployment.
- IPv6 /56 subnet: 256 /64 subnets (256 network segments). Use when you need multiple isolated networks on one VPS.
In practice, you’ll never use anywhere near that many addresses. But a large block lets you organize things cleanly.
When you’d want a routed IPv6 /64 or /56
Running containers or VMs
Running Docker containers, LXC, or nested VMs? Assign each one its own IPv6 address from your /64. No NAT, no port mapping, no conflicts. Each container gets a real, publicly routable address.
IoT and device management
If your VPS hubs IoT devices, each device can get its own IPv6 address from the subnet. Direct device-to-device communication without NAT workarounds.
Hosting multiple services
Running several websites, mail servers, or apps? Give each its own IPv6 address for clean separation instead of routing through a single IP with different ports.
Network lab or testing
Learning networking, studying for certifications, or testing IPv6 configurations? A routed /64 gives you real addresses to work with.
How to request an IPv6 /64 or /56 subnet
- Log into the Client Portal
- Navigate to your VPS server list
- Click the gear icon next to your VPS
- Look for the IPv6 networking section
- Request a /64 or /56 subnet
The subnet gets routed to your VPS’s primary IPv6 address. Once assigned, configure addresses on your server’s network interface.
IPv6 /64 or /56: which one?
For most people, an IPv6 /64 is more than enough. Pick an IPv6 /56 only if you need multiple separate network segments, with several isolated networks inside your VPS, each with its own /64.
If unsure, start with a /64. You can request a /56 later if needs grow.
Every ColossusCloud VPS includes IPv6 by default. Request routed /64 or /56 subnets through the Client Portal. For setup help, see our IPv6 configuration guides.