All Products
Search
Document Center

What is Alibaba Cloud Public DNS?

Last Updated: Jul 08, 2021

This topic describes the overview, development history, and benefits of Alibaba Cloud Public DNS. Public DNS resolves domain names in a fast, secure, and stable way for a variety of terminals.

Overview

Public DNS provides public DNS servers to perform recursive lookups for Internet users across the world. This service is focused on providing secure and fast first hops for Internet access requests from terminals. Public DNS provides recursive lookups by using the HTTP, DNS over HTTPS (DoH), and DNS over TLS (DoT) protocols. Public DNS provides a fast, secure, and stable DNS service for terminals.

The public DNS servers provided by Public DNS use the following IP addresses:

IPv4 addresses:

  • 223.5.5.5

  • 223.6.6.6

IPv6 addresses:

  • 2400:3200::1

  • 2400:3200:baba::1

Development history

Public DNS is a public DNS service that was launched in 2014.

The number of nodes of Public DNS is increasing year by year. All Internet users, regardless of the Internet service provider (ISP), can connect to the public DNS servers and obtain required resources in no time. It uses the EDNS Client Subnet technology. The increase of DNS nodes and improvement of scheduling accuracy ensure high service stability.

Alibaba Cloud has been proactively working to develop and promote IPv6. Public DNS has supported IPv6 since 2019 and became the first public DNS service in China that supports both IPv4 and IPv6. To prevent DNS hijacking and protect user privacy, Public DNS started to support DoT and DoH to achieve encrypted data transmission in 2020.

Key milestones

1. In 2014, Public DNS was launched to provide free DNS services for all Internet users.

2. At the end of June 2020, Public DNS Commercial Edition was released for public preview. The Commercial Edition provides recursive lookups by using HTTP, DoH, and DoT protocols. It also provides the report feature. Public DNS SDKs for Android and iOS were available for download.

3. In April 2021, the public preview period of Public DNS Commercial Edition ended and this service was officially released.

Benefits

Fast response

  • Users can access the nearest DNS node clusters around the world based on the BGP anycast technology.

  • Changes to DNS records in the paid edition of Alibaba Cloud DNS are synchronized to Public DNS in real time. This avoids delay of DNS cache updates caused by the TTL settings, so users can immediately access the latest DNS records.

  • The number of recursive lookups is reduced to minimize latency.

  • User terminals can cache DNS records to accelerate domain name resolution.

  • Public DNS provides a high-performance DNS system based on Data Plane Development Kit (DPDK) to respond to DNS queries.

Security and privacy protection

  • DoH is used to ensure data privacy. Data is encrypted during transmission.

  • Public DNS is independent of specific ISPs and therefore can prevent man-in-the-middle attacks.

Intelligent scheduling and disaster recovery

  • A highly available architecture is adopted. DNS nodes are deployed in multiple data centers across geographic regions.

  • Based on the global CDN resources and IP address library of Alibaba Cloud, public DNS can precisely identify the sources of users and direct these users to the nearest resources.

  • Public DNS provides 17 anycast node clusters and intelligent DNS acceleration services worldwide. Users are routed to the nearest nodes and can obtain DNS responses with the minimum latency.

Comprehensive DNS data system

  • Alibaba Cloud DNS is hosting nearly half of domain names in China. It supports resolutions of both public and private domain names and achieves precise request scheduling.

DingTalk group