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Reverse DNS (PTR Records)

Every IP address you own through Get Real IP can have a custom PTR record — the record that maps an IP address back to a hostname. This is what mail servers and other services look up when they want to know “who owns this IP?”

What is a PTR record?

Section titled “What is a PTR record?”

When someone connects to your server, they see your IP address. If they do a reverse DNS lookup on that IP, they get back the PTR record — a hostname you control.

For example, if your IP is 134.49.198.16 and you set a PTR record of mail.example.com, then:

Terminal window
$ dig -x 134.49.198.16
;; ANSWER SECTION:
42.193.49.134.in-addr.arpa.  300  IN  PTR  mail.example.com.

Why does it matter?

Section titled “Why does it matter?”

Mail servers — Running your own mail server (Postfix, Mailcow, etc.)? Most receiving mail servers check for a matching PTR record as part of spam filtering. Without one, your email will likely be rejected or land in spam.

Trust signals — Security tools, firewalls, and network monitoring systems use reverse DNS to identify connections. A proper PTR record helps your traffic look legitimate.

Debugging — PTR records make logs and traceroute output much more readable.

Setting a PTR record

Section titled “Setting a PTR record”

Before you can set a PTR record, you must create a forward DNS A record with your domain’s DNS provider (Cloudflare, Route 53, Namecheap, etc.) pointing your hostname to your static IP. We verify this before accepting the PTR change — if the forward record isn’t in place or hasn’t propagated yet, the update will be rejected.

  1. At your DNS provider, create an A record: mail.yourdomain.com → your static IP (e.g. 134.49.198.16)
  2. Wait a few minutes for it to propagate, then verify: dig mail.yourdomain.com +short
  3. Go to account.getrealip.net
  4. Open your tunnel
  5. Click Set Reverse DNS next to the IP you want to configure
  6. Enter your hostname (e.g. mail.yourdomain.com)
  7. Click Save

Changes propagate within a few minutes. TTL is 5 minutes.

Requirements and best practices

Section titled “Requirements and best practices”

Use a fully qualified domain name (FQDN) — include the full hostname, e.g. mail.yourdomain.com not just mail. A trailing dot is optional.

One PTR per IP — DNS only supports one PTR record per IP address. If you have multiple services on the same IP (running on different ports), pick the most important one — usually the mail hostname if you’re running a mail server.

Clearing a PTR record

Section titled “Clearing a PTR record”

To remove a PTR record:

  1. Open your tunnel in the dashboard
  2. Click Set Reverse DNS on the IP
  3. Clear the hostname field and save

The record is deleted within a few minutes.

PTR records are also automatically deleted when an IP is deactivated or released back to the pool.

Checking your PTR record

Section titled “Checking your PTR record”

After setting it, verify the record is live:

Terminal window
# Linux/macOS
dig -x 134.49.198.16 +short


# Or using host
host 134.49.198.16


# Or using nslookup
nslookup 134.49.193.x

Online tools: MXToolbox Reverse Lookup, intoDNS

Mail server checklist

Section titled “Mail server checklist”

If you’re running a mail server, PTR records are just one piece. A complete mail reputation setup:

Check Tool
PTR record set dig -x <your-ip>
Forward DNS matches PTR dig <your-hostname>
SPF record on your domain MXToolbox SPF check
DKIM configured MXToolbox DKIM check
DMARC record MXToolbox DMARC check
Not on spam blocklists MXToolbox Blacklist Check