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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.

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Overview

Reverse DNS maps IP addresses back to hostnames using PTR records. This is distinct from forward DNS (hostname to IP). Reverse DNS is required by mail servers for spam reputation checks, improves audit log readability, and is a compliance requirement for many security frameworks. The Dashboard provides a dedicated DNS Reverse interface for managing PTR records on your floating IPs without manually creating reverse zones.
Prerequisites
  • An active Xloud account with appropriate permissions
  • Access to the Xloud Dashboard or CLI configured with credentials
  • API credentials sourced (source openrc.sh)

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How Reverse DNS Works

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View Reverse DNS Entries

Navigate to Network > DNS Reverse. The list shows all floating IPs in your project with their PTR status.
ColumnDescription
AddressThe IP address (clickable to view details)
PTR Domain NameThe hostname this IP resolves to, or empty if not set
StatusActive, Pending, or Error

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Set a PTR Record

1

Navigate to DNS Reverse

Navigate to Network > DNS Reverse. Find the IP address you want to configure.Click the More dropdown in the row actions, then select Set. The Set action is always available and can be used to create a new PTR record or update an existing one.
2

Enter the domain name

In the Set Domain Name PTR dialog, enter the Domain Name — the fully qualified hostname this IP should resolve to.
FieldDetails
Domain Name (required)FQDN ending with a dot (e.g., smtp.example.com.)
Description (optional)Notes about this PTR record
TTL (Time To Live) (optional)Cache duration in seconds. Minimum: 0. Default placeholder: 3600
The domain name should match an A record in your forward DNS zone. Mismatched forward and reverse DNS can cause mail delivery failures and security audit warnings.
3

Confirm the PTR record

Click Confirm. The PTR record enters Pending briefly and transitions to Active.
The PTR Domain Name column shows your configured hostname with Active status.

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Unset a PTR Record

1

Find the PTR record

Navigate to Network > DNS Reverse. Find the IP address with the PTR record you want to remove.
The Unset action is only available when a PTR domain name is configured and the status is Active.
2

Unset the PTR record

Click the More dropdown in the row actions, then select Unset. Confirm the action in the dialog.The PTR domain name is removed and the column returns to empty.

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View PTR Record Details

Click an IP address in the DNS Reverse list to open the detail page.
FieldDescription
AddressThe IP address
PTR Domain NameThe configured hostname
DescriptionNotes about this PTR record
IDUnique identifier
Time To LiveTTL in seconds
StatusActive, Pending, or Error
ActionCurrent action type
From the detail page, you can Set (to update) or Unset the PTR record using the More dropdown in the actions menu.

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IPv6 Reverse DNS

IPv6 PTR records follow the same process as IPv4. The DNS service automatically manages the ip6.arpa. reverse zones for your allocated IPv6 prefixes.
Set PTR record for an IPv6 floating IP
openstack ptr record set \
  <region>:<ipv6-floating-ip-id> \
  ipv6-host.example.com.
IPv6 reverse zones are automatically delegated for your allocated prefix. No manual zone creation is required.

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Next Steps

Manage Records

Add forward DNS records to complement your PTR configuration

Record Types Reference

Reference for all supported DNS record types

Troubleshooting

Resolve PTR record failures and zone delegation issues

DNS Admin Guide

Administer reverse zone pools and nameserver delegation