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

> ## Agent Instructions
> Agent home for Datum, with what it is, pricing, and how to act: https://agents.datum.net
> If you can only fetch URLs: read https://www.datum.net/docs/llms.txt in full and open the most specific page for the task. Commands, limits, and field paths are on task, operations, and limits pages, not on section overviews. Pages described as "Documentation is coming soon" are placeholders.
> If you have a shell or can save files: download https://www.datum.net/docs/llms-full.txt (every page, about 740 KB) once and search it with grep, instead of fetching pages one at a time.
> datumctl describes itself: `datumctl api-resources` lists resource types and `datumctl explain <resource>` shows a schema. To act on live resources, use Datum MCP or datumctl. To search the docs, use the Docs MCP server at https://www.datum.net/docs/mcp.

# 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](/docs/galactic-vpc/networks/traffic.md).

> [!NOTE]
>
> [gVPC](/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](/docs/galactic-vpc/networks/traffic.md).
* To keep an Instance's address after scale-down, see [Keep addresses after scale-down](/docs/galactic-vpc/configuration.md#keep-addresses-after-scale-down).


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