All Products
Document Center


Last Updated: May 19, 2020

Private zone

  • Private zone: A private zone file contains the resource records of domain or subdomain names under your management. It is a tool that most Domain Name System (DNS) software uses to manage domain namespaces.

In PrivateZone, you can create resource records for multiple domain or subdomain names. Resource records for the subdomain names override those for the domain names.

  • Hostname: The prefix of a subdomain name is a hostname, such as www. An at sign (@) is used as the hostname of a root domain name.

  • Record type: The following table lists the record types supported by PrivateZone.

Record type Description
A Points the domain name to an IPv4 address.
AAAA Points the domain name to an IPv6 address.
CNAME Points the domain name to another domain name, namely canonical name.
MX Identifies the mail server for the domain name.
TXT Contains one or more strings, with each enclosed in double quotation marks (“).
PTR Maps an IP address to the domain name.
  • TTL: the amount of time, in seconds, that a recursive DNS server caches records. For example, if the TTL is 60 seconds, the recursive DNS server caches the domain name resolution result, that is, the record, for 60 seconds. DNS queries within 60 seconds will be responded with the record cached.

Associate a private zone with VPCs

  • Virtual Private Cloud (VPC): For more information, see What is VPC.

  • Associate a private zone with VPCs: You can associate a private zone with one or more VPCs. Private zones with the same name cannot be associated with the same VPC. For example, if two private zones are both named, the private zones cannot be associated with the same VPC. Otherwise, when a DNS query is processed, the DNS server cannot determine the resolution result.

A single private zone can be associated with a maximum of 32 VPCs.

  • Disassociate a private zone from VPCs: You can disassociate a private zone from one or more VPCs.

Reverse lookup

  • Reverse lookup: maps an IP address to a domain name. A reverse lookup returns the domain names of an IP address based on the pointer (PTR) record.

  • Reverse lookup zone: the portion of the DNS namespace used for reverse lookup.This portion is called the domain. For example, the zone contains the reverse lookup results for IP addresses that start with 192.168.

  • PTR record: PTR records are DNS resource records that map an IP address to a domain name.