> ## Documentation Index
> Fetch the complete documentation index at: https://datum.net/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Addressing

> How Instances on a gVPC network get private IPv6 addresses, and how the address plan is laid out.

Every Instance gets a private IPv6 address on the network that its workload attaches to. This page describes the address plan. To learn which traffic a network carries, see [Traffic and connecting](https://datum.net/docs/galactic-vpc/networks/traffic.md).

> [!NOTE]
>
> [gVPC](https://datum.net/docs/galactic-vpc/overview.md) is in preview, and the `networking.datumapis.com/v1alpha` API can change.

## How Instances get addresses

Datum assigns all addresses. You don't choose address ranges or plan subnets. The following table describes each level of the address plan:

| Level | Address space | Details |
| - | - | - |
| Network | A `/48` IPv6 prefix | Datum assigns the prefix from the unique local range `fd00::/8` when you create the network. Prefixes don't overlap between networks or projects. The `IPV6PREFIX` column of `datumctl get networks` shows the prefix. |
| Location | A `/64` from the network's prefix | Datum assigns one to each location where Instances on the network run. |
| Instance | A `/96` block from the location's `/64` | Each Instance's network interface owns the whole block. The block's primary address is the Instance's private IPv6 address. |

In the [Cloud Portal](https://cloud.datum.net), open a network under **VPC** > **Networks** to see the address plan for real: the network's `/48`, the `/64` for each location, and the `/96` for each Instance.

![A network Overview showing Network is ready, and Instances grouped by location, us-central-1, us-east-1, and us-west-1, each with its /64 and each Instance with its /96 address](https://mintcdn.com/datum-4926dda5/Xc9AnQUL-oEENeSS/images/galactic-vpc-network-addresses.png?fit=max\&auto=format\&n=Xc9AnQUL-oEENeSS\&q=85\&s=08b1cb745848b1dc836354bb50594342)

A network's address plan: a /48 for the network, a /64 for each location, and a /96 for each Instance

Inside the Instance, the interface is named `eth0`, and it has IPv6 addresses only. Unique local addresses are private: they aren't routable on the internet.

To find your Instances' addresses, run the following command:

```bash theme={null}
datumctl compute instances --workload=WORKLOAD_NAME
```

Replace `WORKLOAD_NAME` with the name of your workload.

The `INTERNAL IP` column shows each Instance's primary private IPv6 address. For all the addresses on an Instance's interface, run `datumctl compute instances describe INSTANCE_NAME`.

## What's next

* To learn which traffic a network carries and how Instances connect, see [Traffic and connecting](https://datum.net/docs/galactic-vpc/networks/traffic.md).
* To keep an Instance's address after scale-down, see [Keep addresses after scale-down](https://datum.net/docs/galactic-vpc/configuration.md#keep-addresses-after-scale-down).


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