Public DNS Resolution

What Is Public DNS Resolution?

Public DNS resolution translates a domain name like www.example.com into an IP address like 1.2.3.4 for routing traffic over the Internet. It is implemented by public DNS servers, including authoritative and non-authoritative DNS servers. An authoritative DNS server stores various DNS records, including A, CNAME, and MX records, and returns accurate responses to DNS queries.

Authoritative DNS services are highly available and scalable authoritative DNS resolution services and domain name management services. They are typically provided by either domain name registrars or cloud service providers.

If you host your domain names on the Huawei Cloud DNS service, DNS will provide public domain name resolution for your website and email servers. Visitors can access your website, mailbox, or web application by entering the desired domain name in the address box of their browser.

Scenarios

Website building
An A record set can map a website domain name to the numerical address of the server where your website is hosted. After an A record set is added for the domain name, users can access your website using the domain name.
Email
An MX record set can map a domain name to the email server address provided by an email service provider. After an MX record set is added for the domain name, emails can be sent and received properly.
Heavy-traffic applications
When a large website is deployed on multiple servers, you can configure weighted routing to distribute requests proportionally among servers. This helps balance server load.
Global traffic scheduling
When visitors are from different carriers or geographical locations, you can configure ISP and region lines to return different resolution results based on the networks or geographical locations of visitors' IP addresses.
Service acceleration with CDN
You can add a CNAME record to map a domain name to the alias domain provided by the CDN service provider. This speeds up website response or download.

Advantages

Deployment in 20+ countries/regions
End users around the world can resolve domain names with low latency.
High performance
Huawei's next-generation Data Plane Development Kit (DPDK) offers resolution acceleration services. This allows DNS to handle hundreds of millions of concurrent queries.
Robust security
DNS defends services against various DDoS attacks with Huawei's powerful anti-DDoS devices and extensive experience in security protections.
Smooth switchover
You can transfer the record sets configured for an in-use website domain to the Huawei Cloud DNS service. You can create a public zone and add record sets on the DNS console before the migration. In this way, your website services are not interrupted during the migration.

Functions

**Table 1** Functions involved in public DNS resolution
Function	Description
Public zone	A public zone hosts the record sets for a domain name that is accessible on the public Internet. You can create, modify, delete, enable, disable, and view public zones. For details, see Overview.
Domain name level	DNS allows you to create public zones for second-level domain names and their subdomains. For domains with single-level suffixes such as .com, you can create zones like example.com and www.example.com. For domains with two-level suffixes such as .com.cn, you can create zones like example.com.cn and www.example.com.cn.
Record set	A record set is a collection of resource records that belong to the same domain name. A record set defines the resolution type and value of a domain name. You can add, modify, delete, view, disable, or enable record sets of the A, CNAME, MX, AAAA, TXT, SRV, NS, and CAA types for public zones. For details, see Overview.
Reclaiming a public zone	If a public zone has been created for your domain name by another user, you can reclaim it by proving that you are the holder of the domain name. For details, see Reclaiming a Public Zone.
Wildcard DNS record set	For a second-level domain, you can add a record set with the record set name set to an asterisk (*), so traffic will be routed to all subdomains of that domain name. For details, see Configuring a Wildcard DNS Record Set.
TTL	Time-to-live (TTL) specifies how long a local DNS server can cache record sets before it must request fresh information from an authoritative server. It is measured in seconds. The TTL value ranges from 1 to 2147483647.
Weight	The weight assigned to each record determines the proportion of DNS queries that will be routed to that record. If a domain name has multiple records with the same type and line, you can set different weights for each record. For details, see Configuring Weighted Routing.
Batch operations	You can add and transfer zones, and add, modify, and delete record sets in batches.