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How Can I Map the Private IP Address of an ECS to a Domain Name?

You can configure PTR records to allow end users to query domain names based on IP addresses.

To map the private IP address of an ECS to a domain name, you must create a private zone and add a PTR record to the zone.

To add a PTR record, you may refer to Creating a PTR Record.

The domain name for the PTR record must be in the x.x.x.x.in-addr.arpa format. in-addr.arpa is the domain name suffix used for reverse resolution.

For example, if the private IP address is 192.168.1.10, the domain name is 10.1.168.192.in-addr.arpa.

You need to create a private zone with the domain name set to 192.in-addr.arpa and add a PTR record with the Name field set to 10.1.168.

Creating a Private Zone

  1. Go to the Private Zones page.
  2. Click Create Private Zone.
  3. Configure the parameters based on Table 1.
    Table 1 Parameters for creating a private zone

    Parameter

    Description

    Example Value

    Domain Name

    Domain name you use to access the cloud servers or cloud services.

    Ensure that the domain name suffix is in-addr.arpa.

    192.in-addr.arpa

    VPC

    VPC to be associated with the private zone.

    Select the VPC you want to associate with the private zone.

    -

    Email

    (Optional) Email address of the administrator managing the private zone.

    Recommended email address: HOSTMASTER@Domain name

    For more information about the email address, see Why Was the Email Address Format Changed in the SOA Record?

    HOSTMASTER@example.com

    Enterprise Project

    Enterprise project associated with the private zone.

    You can manage private zones by enterprise project.

    NOTE:

    This parameter is available and mandatory only when Account Type is set to Enterprise Account.

    When setting this parameter, note the following:

    default

    Tag

    (Optional) Identifier of a resource.

    Each tag contains a key and one or more values. You can add a maximum of 10 tags to a zone.

    For details about tag key and value requirements, see Table 2.

    NOTE:

    If you have configured tag policies for DNS, you need to add tags to your private zones based on the tag policies. If you add a tag that does not comply with the tag policies, private zones may fail to be created. Contact the administrator to learn more about tag policies.

    example_key1

    example_value1

    Description

    (Optional)

    Supplementary information about the zone.

    You can enter a maximum of 255 characters.

    This is a private zone.
    Table 2 Tag key and value requirements

    Parameter

    Requirements

    Example Value

    Key
    • Cannot be left blank.
    • Must be unique for each resource.
    • Can contain a maximum of 36 characters.
    • Cannot start or end with a space nor contain special characters =*<>\,|/

    example_key1

    Value
    • Cannot be left blank.
    • Can contain a maximum of 43 characters.
    • Cannot start or end with a space nor contain special characters =*<>\,|/

    example_value1
  4. Click OK.
  5. Switch back to the Private Zones page.
    You can view the created private zone in the private zone list.

    You can click the domain name to view SOA and NS record sets automatically generated for the zone.

    • The SOA record set includes administrative information about your zone, as defined by the Domain Name System (DNS).
    • The NS record set defines the authoritative DNS servers for the domain name.

Adding a PTR Record Set

  1. On the Private Zones page, click the domain name of the private zone you created.

    The Record Sets tab is displayed.

  2. Click Add Record Set.

    The Add Record Set dialog box is displayed.

    Figure 1 Add Record Set
  3. Configure the parameters based on Table 3.
    Table 3 Parameters for adding a PTR record set

    Parameter

    Description

    Example Value

    Name

    Part of the private IP address in reverse order.

    10.1.168

    For example, if the IP address is 192.168.1.10, the domain name in the PTR record must be 10.1.168.192.in-addr.arpa.

    • If the domain name is 192.in-addr.arpa, enter 10.1.168.
    • If the domain name is 1.168.192.in-addr.arpa, enter 10.

    Type

    Type of the record set.

    PTR – Map IP addresses to domains

    TTL (s)

    Cache duration of the record set, in seconds.

    Default value: 300

    Value

    Domain name mapped to the IP address.

    You can enter only one name.

    mail.example.com

    Tag

    (Optional) Identifier of a record set. Each tag contains a key and a value. You can add a maximum of 10 tags to a record set.

    For details about tag key and value requirements, see Table 2.

    NOTE:

    If you have configured tag policies for DNS, you need to add tags to your record sets based on the tag policies. If you add a tag that does not comply with the tag policies, record sets may fail to be created. Contact the administrator to learn more about tag policies.

    example_key1

    example_value1

    Description

    (Optional) Supplementary information about the PTR record set.

    This parameter is displayed when you expand More Settings.

    The PTR record is for reverse resolution.
  4. Click OK.
  5. Switch back to the Record Sets tab.

    The added record set is in the Normal state.

Parent topic: Private Zones