## Why you Shouldn’t Utilize Global Anycast DNS in China

Summary: Anycast DNS is a standard feature in authoritative DNS services, routing inbound queries to the nearest servers. However, in China, this practice is risky due to the extensive filtering and controls imposed on internet traffic within the country. NS1’s approach, Nameserver Acceleration, is detailed as an effective alternative.

Anycast is a standard feature in every authoritative DNS service, routing inbound queries to the closest servers geographically. However, in mainland China, this practice is not recommended. The Chinese internet is segregated from the rest of the world, requiring any DNS query that traverses in or out to pass through various filters and controls, resulting in a substantial performance decrease.

Numerous authoritative DNS providers address this challenge by expanding their network into mainland China to resolve traffic within the country. Although this seemingly logical approach enhances the likelihood of responding from a server within the system of filters and controls, it is not foolproof. Despite numerous points of presence (PoPs) in mainland China, the Border Gateway Protocol (BGP) often directs users in China to resolving servers in neighboring countries, causing a significant performance hit.

Contrary to the anycast approach, which relies on BGP to locate a resolver, NS1’s Nameserver Acceleration geolocates the query source, utilizing traffic steering technology to determine which network should respond to a query. For requests from China, NS1’s DNS servers in China handle the response while the global anycasted network handles requests from other regions.

NS1’s Nameserver Acceleration works by adding an extra step to the resolution process, ensuring that traffic routed to a nearby country is prevented. Although this additional step slightly extends the query resolution process, the impact on performance is negligible. In comparison to the performance drag induced by the system of filters and controls, it is clearly worthwhile.

The approach offered by NS1 yields significant advantages, with DNS response times in mainland China being over three times faster on average compared to other networks. NS1 also streamlines DNS management for global businesses with a substantial user base in mainland China, integrating all technical aspects and traffic steering within a single control plane.

**FAQ**

1. **What is Anycast DNS?**
Anycast DNS is a networking technique that routes traffic to the nearest available server based on the user’s location, ensuring optimal performance for inbound queries.

2. **Why is using Global Anycast DNS in China not recommended?**
The internet in mainland China is regulated by filters and controls, causing significant performance degradation for DNS queries that cross into or out of the country. Thus, utilizing a standard global anycast DNS approach may lead to poor performance for users in China.

3. **How does NS1’s Nameserver Acceleration work?**
Nameserver Acceleration geolocates the query source and utilizes traffic steering technology to determine whether the response should be handled by DNS servers in China for requests from China and the global anycasted network for requests from other geographical locations.

4. **What are the benefits of NS1’s Managed DNS for China?**
NS1’s Managed DNS for China offers improved performance for DNS queries originating from mainland China and streamlines DNS management through a single control plane without the need for an ICP license.

Source: [IBM NS1](https://www.ibm.com/blogs/network/dns-management-approach-china/)