Cloud DNS FAQ
What is a domain name system (DNS)?
The Domain Name System (DNS) determines Internet domain name-to-address and address-to-name resolutions. All domains and their components, such as mail servers, use DNS to resolve to the appropriate locations. For example, DNS is used to turn ‘www.rackspace.com’ into the computer addressable IP address ‘18.104.22.168’.
DNS servers are usually set up in a master-slave relationship such that failure of the master invokes the slave. DNS servers might also be clustered or replicated such that changes made to one DNS server are automatically propagated to other active servers.
What types of customers or accounts can access Cloud DNS?
Anyone who has a Rackspace Cloud account can access the Cloud DNS service. Existing Cloud customers have access to the Rackspace Cloud DNS by default.
Where can I find the Cloud DNS API documentation?
See the Cloud DNS Developer Guide for information about the Cloud DNS API.
Billing and usage
How much does this service cost?
Cloud DNS is currently available at no additional cost and is intended for use with Cloud accounts that have provisioned and active resources.
Existing product compatibility
Can this service be used for Dedicated Servers?
No. The Cloud DNS service is only available for Cloud account resources. Managed and Dedicated customers with RackConnect (that is, customers who also have a Cloud account) have access but can only use the service to manage DNS for their Rackspace Cloud resources.
How does this work for Hybrid customers?
A Hybrid customer can continue to use the MyRackspace Portal to manage domains for their dedicated resources and can use Cloud DNS to manage domains for their Cloud resources.
Note: Duplicate domains cannot exist between Managed Hosting and Cloud Hosting resources.
Accessing Cloud DNS
How do I authenticate with the Cloud DNS API?
The process for authenticating with the Cloud DNS API is the same as when authenticating with all other Rackspace Cloud APIs.
To authenticate, you must supply your username and API access key in x-headers.
- Use your Rackspace Cloud username as the username for the API. Place it in
- View and reset your API key in the
Rackspace Cloud Control Panel. Place it in the
For full authentication details, see the Cloud DNS Developer Guide.
What account number do I use to access the service?
Customers should use their existing Cloud account number.
What is the difference between US and UK Cloud DNS?
The functionality is the same. The only difference is that the US and the UK each have the following separate API endpoints:
- US =
- UK =
Features and functionality
What DNS management operations does the Cloud DNS API support?
Customers can create, modify, remove, and list domains, subdomains, and records.
Additionally, users can search domains by filtering. We do not support filtering records.
For a full list of supported API operations, see the Cloud DNS Developer Guide.
What record types does Cloud DNS support?
The Cloud DNS API currently supports the following record types:
Note: You cannot create Service-Oriented Architecture (SOA) records, which are handled by the system, but you can modify the Time to Live (TTL) and email address.
The service supports
SPF records through formatting
TXT records with
custom attributes indicating the record type. We do not currently support the
RR type as defined in RFC 4408.
For more information about supported record types, see the Cloud DNS Developer Guide.
Can I import and export domains?
Yes, you can do this by using the API. You can import a domain from external providers by using a
bind9-formatted zone file. Similarly, you can export their domain to a
bind9-formatted file. Currently, you cannot transfer zones from MyRackspace
to Cloud DNS and should contact Support to request a domain transfer from
dedicated resources to Cloud resources.
What are the Rackspace DNS servers?
Our default DNS servers are:
What type of DNS network does Rackspace use?
Rackspace leverages a globally distributed Anycast network. Currently, we have
DNS servers located in Texas, Virginia, Chicago, and London. Using Anycast, we
broadcast the IP addresses for
each location. All DNS queries generally go to the geographically-closest
name servers, giving you faster results no matter where your queries originate.
Additionally, all of our DNS servers are monitored 24/7, and if an entire
data center were to fail, or even if all of the DNS servers within a specific
data center were to fail, the DNS queries automatically start going to the
next best location.
What are the limitations of the search functionality?
You can search for domains within your own account. The functionality does not allow you to search for records.
Do my TTL settings expire?
What are the default TTLs for domains and records?
When a domain or record is created, and no TTL is specified, a default value of 3600 seconds is used. When the domain or record TTL is supplied by the user through a create or update operation, the specified TTL values must be 300 seconds or more.
How long does it take for DNS changes to be propagated globally?
Typical DNS propagation to Rackspace name servers (globally) might take up to one minute. Propagation refers to the time between when a change is made to a customer’s records and when the change takes effect on our name servers. A large amount of changes made simultaneously might take 2 to 3 minutes.
If a new domain is added or an existing domain is deleted, this might take a few minutes to propagate to our Rackspace name servers.
When changing name servers for a domain, complete propagation takes about 2 days for most domains. This is enforced by the registries.
Are there API rate limits?
By default, all accounts have a preconfigured set of thresholds (or limits) to manage capacity and prevent abuse of the system. The system recognizes two kinds of limits: rate limits and absolute limits. Rate limits are thresholds that are reset after a certain amount of time passes. Absolute limits are fixed. See the Cloud DNS Developer Guide for more information on rate limits.
How many Cloud DNS domains and records can I have?
By default, Cloud DNS users can have up to 500 domains (including sub-domains)
and 500 records per domain per Cloud account. When a user submits a request to
create new domains, records, or sub-domains, the system accepts the request
only if the total number of existing domains plus requested domains, sub-domains,
or records is within the account limits. If the total exceeds the account limit,
the entire request is rejected, and a
413 Request Entity Too Large message is
returned. See the
Cloud DNS Developer Guide
for more information on absolute limits.
How can I create a Cloud DNS ticket?
Submit Cloud DNS requests by using the standard Support ticket interface in the Control Panel.
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