The DNS service helps you create and manage your DNS zones.
See Records for additional information.
Watch a video introduction to the service.
What is DNS?
The Domain Name System (DNS) translates human-readable domain names to machine-readable IP addresses. A DNS nameserver stores the DNS records for a zone , and responds with answers to queries against its database. When you type a domain name into a browser, the computer OS queries several DNS nameservers until it finds the authoritative nameserver for that domain. The authoritative nameserver then responds with an IP address or other requested record data. The answer is then relayed back to the browser and the DNS record is resolved to the web page.
- Public DNS: Create zones with publicly available domain names reachable on internet. You need to register with a DNS registrar (delegation).
- Private DNS: Provides hostname resolution for applications running within and between virtual cloud networks
- Secondary DNS: Secondary DNS provides redundancy for primary DNS servers .
- Reverse DNS: (RDNS) Maps an IP address to a hostname .
DNS Service Components
The following list describes the components used to build a DNS zone and make it accessible from the internet.
- Domain names identify a specific location or group of locations on the Internet as a whole. A common definition of domain is the complete part of the DNS tree that has been delegated to a user's control. For example,
- A zone is a part of the DNS namespace. A Start of Authority record (SOA) defines a zone. A zone contains all labels underneath itself in the tree, unless otherwise specified.
- Labels are prepended to the zone name, separated by a period, to form the name of a subdomain. For example, the
docs.us-ashburn-1.oraclecloud.comare labels. Records are associated with these domains.
- child zone
- Child zones are independent subdomains with their own Start of Authority and Name Server (NS) records. The parent zone of a child zone must contain NS records that refer DNS queries to the name servers responsible for the child zone. Each child zone creates another link in the delegation chain.
- resource records
- A record contains specific domain information for a zone. Each record type contains information called record data (RDATA). For example, the RDATA of an A or AAAA record contains an IP address for a domain name, while MX records contain information about the mail server for a domain. OCI normalizes all RDATA into the most machine readable format. The returned presentation of your RDATA may differ from its initial input. For more information about RDATA, please see Supported DNS Resource Record Types.
- The name servers where DNS is hosted and managed.
Domain Name Normalization
The OCI DNS service normalizes domain names that use Internationalized Domain Names (IDNs) by converting them into Punycode format. Requests to OCI DNS can use IDNs, but responses use Punycode. For example, if you create a zone and provide an IDN zone name, the resulting response for the created zone uses Punycode.
Ways to Access the DNS Service
You can access Oracle Cloud Infrastructure (OCI) by using the Console (a browser-based interface), REST API, or OCI CLI. Instructions for using the Console, API, and CLI are included in topics throughout this documentation. For a list of available SDKs, see Software Development Kits and Command Line Interface.
Authentication and Authorization
Each service in Oracle Cloud Infrastructure integrates with IAM for authentication and authorization, for all interfaces (the Console, SDK or CLI, and REST API).
An administrator in your organization needs to set up groups , compartments , and policies that control which users can access which services, which resources, and the type of access. For example, the policies control who can create new users, create and manage the cloud network, launch instances, create buckets, download objects, and so on. For more information, see Getting Started with Policies. For specific details about writing policies for each of the different services, see Policy Reference.
If you’re a regular user (not an administrator) who needs to use the Oracle Cloud Infrastructure resources that your company owns, contact your administrator to set up a user ID for you. The administrator can confirm which compartment or compartments you should be using.
DNS Service Capabilities and Limits
The OCI DNS service is limited to 1000 zones per account and 25,000 records per zone. Customers with zone and record size needs exceeding these values are encouraged to contact support at support.oracle.com. Zone file uploads are limited to 1 megabyte (MB) in size per zone file. If a zone file is larger than 1 MB, you need to split the zone file into smaller batches to upload all the zone information.
For more information and a workaround for this limitation, see Zone File Limitations and Considerations.
Required IAM Service Policy
To use Oracle Cloud Infrastructure, you must be granted security access in a policy by an administrator. This access is required whether you're using the Console or the REST API with an SDK, CLI, or other tool. If you get a message that you don’t have permission or are unauthorized, verify with your administrator what type of access you have and which compartment to work in.
Permissions are required for managing DNS. The level of access is cumulative as you go from
manage. For example, the
read verb covers permissions to read and inspect. The
manage verb covers permissions for inspect, read, update, create, delete, and move.
- To enable all operations on zones for a specific user group:
Allow group <GroupName> to manage dns in tenancy
- To enable a specific group to read zones:
Allow group <GroupName> to read dns-zones in tenancy
- To create a read-only DNS management group:
Allow group <GroupName> to read dns in tenancy