Overview

A reverse DNS record, also called a PTR (pointer) record, maps an IP address back to a hostname. Reverse DNS is important for running a mail server: many receiving servers reject or spam-score mail from IPs without a matching PTR. This article shows how to set reverse DNS for your Pod's IP address in the ALYPOD Console.

Before you begin

• A domain you control, with an A record pointing the hostname to the Pod's public IP.
• Access to the ALYPOD Console.

Steps

1. Create the forward record first. In the DNS zone for your domain, add an A record such as mail.example.com pointing to your Pod's IPv4 address (and an AAAA record if you use IPv6).
2. Log in to account.alypod.com and open the ALYPOD Console.
3. Go to your Pod and open the Networking tab.
4. Find the IP address you want to edit and click Reverse DNS (or the edit icon next to the PTR field).
5. Enter the hostname, for example mail.example.com, and save.
6. Wait for the change to publish. You can confirm it with:

```bash dig -x 203.0.113.10 +short

or

host 203.0.113.10 ```

The answer should return the hostname you configured.

Good practice

• The PTR hostname should match the hostname your mail server announces in its SMTP banner (myhostname in Postfix).
• Only one PTR can exist per IP address.
• Some receiving servers also check that the forward A record matches the PTR. Keep both in sync.

Troubleshooting

• Problem: dig -x still returns nothing. Solution: DNS changes take time to propagate; allow up to a few hours and try a public resolver with dig @1.1.1.1 -x <ip>.
• Problem: You cannot change the PTR. Solution: Make sure you are editing the IP address that is actually assigned to your Pod; unassigned or additional IPs must be routed correctly before a PTR can be set.

Related articles

• [Setting up email DNS (SPF, DKIM, DMARC)]
• [Managing DNS records (A, AAAA, CNAME, MX, TXT)]