Functions

Table 1 lists basic functions of the DNS service.

Before you use the DNS service, you'd better get familiar with Product Concepts to better understand the functions.

**Table 1** Common DNS functions
Category	Function	Description
Private domain resolution	Private zone	You can create private domain names that take effect in associated VPCs. DNS allows you to create, modify, delete, and view private zones, associate private zones with VPCs, and disassociate private zones from VPCs. Private zones can be created without the need to register domain names. The private zone must be unique in the associated VPC. For details, see Overview.
	Associating a private zone with or disassociating a private zone from a VPC	You can associate a private zone with or disassociate a private zone from a VPC. For details, see Associating a VPC with a Private Zone and Disassociating a VPC from a Private Zone.
	Record set	A record set is a group of resource records that define the resolution type and value of a domain name. You can add, modify, delete, or view A, CNAME, MX, AAAA, TXT, PTR, and SRV record sets for private zones. For details, see Overview.
	Wildcard resolution	You can add record sets for all subdomains of a private domain name. DNS provides resolution services for all subdomains. For details, see Creating a Wildcard DNS Record Set.
	TTL	TTL is short for time to live, which specifies the cache period of resource records on a local DNS server, in seconds. The TTL value ranges from 300 to 2147483647.
	Batch deleting private zones	You can delete multiple private zones at a time.
Record sets	Searching for record sets globally	DNS allows you to centrally manage record sets, including the following: Searching for record sets by status, type, name, value, ID, or tag Modifying or deleting record sets of private zones For details, see Searching for Record Sets Globally.
Tag	Resource tag	You can configure tags for private zones and record sets. You can also use predefined tags provided by Tag Management Service (TMS) to quickly associate tags with resources.
Quota	Quota adjustment	Quotas are enforced for service resources on the platform to prevent unforeseen spikes in resource usage. Quotas can limit the number of resources available to users, for example, the maximum number of zones or record sets that you can create. If the existing resource quota cannot meet your service requirements, you can apply for a higher quota. For details, see Quota Adjustment.