# Globally unique domain zone

**Make sure you understand the [basic concepts]((../nns/README.md)) of `NNS`.**

`Globally Unique Domains Zone` (`GUDZ`) is an extension of `NNS` that ensures unique names across multiple domain zones. When this option is enabled, all newly created domains will automatically receive a corresponding alias in the designated global zone. Deleting a domain will also remove its alias from the global zone.

It's important to note that this feature is not retroactive: domains created before this option is enabled will not receive a global alias. Likewise, if the option is later disabled, domains that already have a `GUDZ` alias will retain their records. To fully disable `GUDZ`, all domains must be recreated with the option turned off.

To enable `GUDZ`, add a `cnametgt=$(global domain)` `TXT` record that specifies the global zone.

**Example:**

Domains:
- `poland`
- `sweden`
- `animals.org`

![](img/GUDZ-2.png)

It is necessary to associate the domain zones `.poland` and `.sweden` into the global zone `.animals`.

![](img/GUDZ-1.png)

Create domains:

```
frostfs-adm morph nns register --name="poland" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
frostfs-adm morph nns register --name="sweden" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
frostfs-adm morph nns register --name="org" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
frostfs-adm morph nns register --name="animals.org" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```

Add the `cnametgt` records:

```
frostfs-adm morph nns  add-record --name="poland" --data="cnametgt=animals.org" --type="txt" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml 
frostfs-adm morph nns  add-record --name="sweden" --data="cnametgt=animals.org" --type="txt" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml 
```

Create a domain with mapping to the global zone:

```
frostfs-adm morph nns register --name="bober.poland" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```

Add any `TXT` record

```
frostfs-adm morph nns  add-record --name="bober.poland" --data="CID" --type="txt" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml 
```

Verify that the created domain has alias in the global zone

```
frostfs-adm morph nns tokens -v --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml

balance.frostfs
animals.org
group.frostfs
container
org
container.frostfs
proxy.frostfs
policy.frostfs
alphabet0.frostfs
sweden
frostfsid.frostfs
bober.animals.org (CNAME: bober.sweden)
netmap.frostfs
frostfs
poland
bober.poland
```

Create of a conflicting domain
```
frostfs-adm morph nns register --name="bober.sweden" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml

unable to register domain: script failed (FAULT state) due to an error: at instruction 1263 (THROW): unhandled exception: "global domain is already taken: bober.animals.org. Domain: bober.sweden
```

**Disable GUDZ**
Delete `cnametgt` records

```
frostfs-adm morph nns delete-records --type=txt --name=poland --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```
Create `hamster.poland` and `hamster.sweden`
```
frostfs-adm morph nns register --name="hamster.poland" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
frostfs-adm morph nns register --name="hamster.sweden" --email="email@email.email" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```
`hamster.poland` and `hamster.sweden` does not have alias
```
frostfs-adm morph nns tokens -v --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
balance.frostfs
animals.org
group.frostfs
container
org
container.frostfs
proxy.frostfs
policy.frostfs
alphabet0.frostfs
sweden
frostfsid.frostfs
bober.animals.org (CNAME: bober.poland)
netmap.frostfs
frostfs
poland
bober.poland
hamster.poland
```
Delete global alias of `bober.poland`

```
 frostfs-adm morph nns delete-records --name="bober.poland" --type="txt" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```


```
frostfs-adm morph nns tokens -v --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
balance.frostfs
animals.org
group.frostfs
container
org
container.frostfs
proxy.frostfs
policy.frostfs
alphabet0.frostfs
sweden
frostfsid.frostfs
netmap.frostfs
frostfs
poland
bober.poland
hamster.poland
```
Delete `bober.poland`
```
 frostfs-adm morph nns delete --name="bober.poland" --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
```

```
frostfs-adm morph nns tokens -v --config /home/achuprov/Documents/work/frostfs-dev-env/frostfs-adm.yml
balance.frostfs
animals.org
group.frostfs
container
org
container.frostfs
proxy.frostfs
policy.frostfs
alphabet0.frostfs
sweden
frostfsid.frostfs
netmap.frostfs
frostfs
poland
hamster.poland
```