# Set reverse DNS for your server

> What reverse DNS (PTR) records are, when you need one, how to set one in the panel or with vps9, and how to check it with dig.

Source: https://vpsnine.com/help/reverse-dns · Updated: 2026-10-10

Forward DNS turns a name into an address: `mail.example.com` to `203.0.113.42`. Reverse DNS goes the other way, from `203.0.113.42` back to a name, using a PTR record. You set forward records wherever your domain's DNS lives. Reverse records belong to whoever owns the IP address, and for your server that's us, so it's set through VPSNine.

## When you need it

You need it if you send email from the server. Plenty of mail servers reject or junk mail from an address with no reverse DNS, or whose reverse name doesn't point back to the same address. Set it before you send anything, and read [Sending email: port 25](https://vpsnine.com/help/open-port-25) too.

It's also nice in logs and `traceroute` output, where a name is easier to recognise than a number. For a plain web server, though, you can skip it.

## Create the forward record first

The reverse record should match a forward one, so start there. At your DNS provider:

```text
mail.example.com.  A     203.0.113.42
mail.example.com.  AAAA  2001:db8:9::2
```

Check it from your computer:

```bash
dig +short mail.example.com A
```

It has to return your server's address before you go on.

## Set the reverse record

In the panel, open the server and choose **reverse dns**. There's a box for the server's IPv4 address and another for its IPv6 address, if it has one. Type the name and press **set reverse dns**.

With the [vps9 CLI](https://vpsnine.com/help/install-the-vps9-cli), it's one command per address:

```bash
vps9 rdns web-1 set 203.0.113.42 mail.example.com
vps9 rdns web-1 set 2001:db8:9::2 mail.example.com
```

Before we accept the name, we look it up and check that it points to that address: the `A` record for the IPv4 address, `AAAA` for IPv6. If the name has no such record, points somewhere else, or doesn't answer within 3 seconds, you get a message saying which, and nothing changes. Fix the forward record, give it a minute, and try again.

Reverse records are set by hand for now. A request shows as **requested, waiting to be set** until it's done, usually within a working day, and then as **live**. To take a name off, press **clear** in the panel or run `vps9 rdns web-1 rm 203.0.113.42`. It shows as **being removed** until we've reset it.

You get ten tries an hour across your account. Clears count, and so do tries the forward check refuses. When you delete a server, we reset its reverse DNS before its addresses go to anyone else.

## Check it

```bash
dig +short -x 203.0.113.42
dig +short -x 2001:db8:9::2
```

Once the panel says **live**, each should print `mail.example.com.`, trailing dot included. Resolvers can hang on to the old answer for up to the record's TTL.

Then close the loop:

```bash
dig +short mail.example.com A
```

That should give back the same address you started with. Mail servers call this forward-confirmed reverse DNS, and it's what they actually check.

If `dig -x` still shows nothing or the old name, your resolver has it cached; wait out the TTL. If the reverse name doesn't resolve back, the forward `A` or `AAAA` record is the one to fix. If a request is still waiting after a working day, or shows **failed**, [open a support ticket](https://my.vpsnine.com/support/new?category=network) with the address.