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

# DNS Backend Configuration

> Configure the Xloud DNS backend driver and nameserver pool targets through XDeploy. View current pool configuration, manage zone assignments, and update.

## Overview

The DNS service backend driver determines which DNS server software is used to serve
zone data. The backend is configured through XDeploy and the `xavs-ansible` deployment
tool. This page covers viewing and managing current pool configuration and assigning
zones to specific pools.

<Warning>
  **Administrator Access Required** — This operation requires the `admin` role. Contact your
  Xloud administrator if you do not have sufficient permissions.
</Warning>

<Note>
  **Prerequisites**

  * Administrator credentials sourced via `openrc.sh`
  * Access to XDeploy for DNS service configuration changes
</Note>

***

## View Current Configuration

<Tabs>
  <Tab title="List DNS pools" icon="list">
    ```bash title="List DNS pools" theme={null}
    openstack zone pool list
    ```

    ```bash title="Show pool detail" theme={null}
    openstack zone pool show <pool-id>
    ```

    Pool detail fields:

    | Field           | Description                                                         |
    | --------------- | ------------------------------------------------------------------- |
    | `name`          | Pool identifier used when assigning zones                           |
    | `description`   | Administrative description                                          |
    | `nameservers`   | List of authoritative nameserver hostnames for this pool            |
    | `targets`       | Backend server endpoints the worker pushes zone data to             |
    | `also_notifies` | Additional servers notified of zone changes (for AXFR)              |
    | `attributes`    | Key-value tags used to match zones to pools via scheduling policies |
  </Tab>

  <Tab title="Verify pool health" icon="heart-pulse">
    Verify that the pool's nameservers are authoritatively answering queries:

    ```bash title="Check zone on each nameserver" theme={null}
    dig @<nameserver-ip> example.com. SOA +norecurse
    ```

    A healthy pool nameserver returns the SOA record with `AUTHORITY: 1`. If the
    nameserver returns `SERVFAIL`, the zone has not synchronized to that nameserver.
  </Tab>
</Tabs>

***

## Assign a Zone to a Pool

By default, new zones are assigned to the default pool based on scheduling policies.
You can override pool assignment:

```bash title="Show zone's current pool assignment" theme={null}
openstack zone show <zone-name> -c masters -c attributes
```

```bash title="Assign a zone to a specific pool" theme={null}
openstack zone set <zone-name> --attributes pool_id:<pool-id>
```

<Warning>
  Reassigning a zone to a different pool triggers a full zone synchronization to the
  new pool's nameservers. During synchronization, queries may return stale data from
  the old pool if resolver caches have not expired.
</Warning>

***

## Pool Configuration Reference

Pool configuration is managed through XDeploy service configuration files and applied
via `xavs-ansible deploy`. The following fields control backend behavior:

| Parameter       | Description                              | Example                 |
| --------------- | ---------------------------------------- | ----------------------- |
| `backend`       | DNS server backend type                  | `bind9`, `pdns4`        |
| `targets`       | Backend RNDC/API endpoints for zone push | `<host>:<port>`         |
| `nameservers`   | Public-facing nameserver FQDNs           | `ns1.example.com.`      |
| `also_notifies` | Hosts to NOTIFY after zone changes       | Secondary server IPs    |
| `attributes`    | Scheduling attributes                    | `service_tier: premium` |

***

## Next Steps

<CardGroup cols={2}>
  <Card title="Pool Management" href="/services/dns/pool-management" color="#197560">
    Add nameservers, configure attributes, and manage pool health
  </Card>

  <Card title="Zone Transfers" href="/services/dns/zone-transfers" color="#197560">
    Configure AXFR/IXFR zone transfer policies
  </Card>

  <Card title="Architecture" href="/services/dns/architecture" color="#197560">
    Understand the DNS service topology and component roles
  </Card>

  <Card title="Admin Troubleshooting" href="/services/dns/admin-troubleshooting" color="#197560">
    Diagnose backend connectivity and synchronization failures
  </Card>
</CardGroup>