Amazon Route 53
API Reference


A complex type that contains information about the records that you want Route 53 to create when you register an instance.



The amount of time, in seconds, that you want DNS resolvers to cache the settings for this record.


Alias records don't include a TTL because Route 53 uses the TTL for the AWS resource that an alias record routes traffic to. If you include the AWS_ALIAS_DNS_NAME attribute when you submit a RegisterInstance request, the TTL value is ignored. Always specify a TTL for the service; you can use a service to register instances that create either alias or non-alias records.

Type: Long

Valid Range: Minimum value of 0. Maximum value of 2147483647.

Required: Yes


The type of the resource, which indicates the type of value that Route 53 returns in response to DNS queries.

Note the following:

  • A, AAAA, and SRV records: You can specify settings for a maximum of one A, one AAAA, and one SRV record. You can specify them in any combination.

  • CNAME records: If you specify CNAME for Type, you can't define any other records. This is a limitation of DNS—you can't create a CNAME record and any other type of record that has the same name as a CNAME record.

  • Alias records: If you want Route 53 to create an alias record when you register an instance, specify A or AAAA for Type.

  • All records: You specify settings other than TTL and Type when you register an instance.

The following values are supported:


Route 53 returns the IP address of the resource in IPv4 format, such as


Route 53 returns the IP address of the resource in IPv6 format, such as 2001:0db8:85a3:0000:0000:abcd:0001:2345.


Route 53 returns the domain name of the resource, such as Note the following:

  • You specify the domain name that you want to route traffic to when you register an instance. For more information, see RegisterInstance:Attributes.

  • You must specify WEIGHTED for the value of RoutingPolicy.

  • You can't specify both CNAME for Type and settings for HealthCheckConfig. If you do, the request will fail with an InvalidInput error.


Route 53 returns the value for an SRV record. The value for an SRV record uses the following values:

priority weight port service-hostname

Note the following about the values:

  • The values of priority and weight are both set to 1 and can't be changed.

  • The value of port comes from the value that you specify for the AWS_INSTANCE_PORT attribute when you submit a RegisterInstance request.

  • The value of service-hostname is a concatenation of the following values:

    • The value that you specify for InstanceId when you register an instance.

    • The name of the service.

    • The name of the namespace.

    For example, if the value of InstanceId is test, the name of the service is backend, and the name of the namespace is, the value of service-hostname is:

If you specify settings for an SRV record and if you specify values for AWS_INSTANCE_IPV4, AWS_INSTANCE_IPV6, or both in the RegisterInstance request, Route 53 automatically creates A and/or AAAA records that have the same name as the value of service-hostname in the SRV record. You can ignore these records.

Type: String

Valid Values: SRV | A | AAAA | CNAME

Required: Yes

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following:

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