A DNS check from our Hohhot node queries your domain's authoritative nameservers directly and records the response. This bypasses Chinese carrier recursive resolvers — which are known to return poisoned or NXDOMAIN responses for GFW-blocked domains — and queries your nameservers directly from the Alibaba Cloud AS37963 IP space. A successful response confirms your authoritative DNS is reachable and correctly configured from inside China.

Chinese carrier DNS resolvers apply GFW blocklist rules at the resolver level. Domains on the blocklist receive falsified responses (often pointing to a non-routable IP or returning NXDOMAIN). Our DNS check queries the authoritative tier directly, which sidesteps this resolver-level pollution and shows what the nameserver itself returns. If your authoritative nameservers are reachable from China but the domain is GFW-blocked, the DNS check will return a valid record while an HTTP check will fail.

If you use GeoDNS to direct Chinese users to a China-hosted CDN or origin, a DNS check from our Hohhot node should return the IP assigned to the Chinese or Asia-Pacific geo-zone. AS37963 (Alibaba Cloud) is a well-known Chinese ASN and should be correctly classified by all major GeoDNS providers. If the check returns a US or European IP instead, your GeoDNS policy is not matching Alibaba Cloud's address space correctly.

China's public internet is controlled by three state-owned carriers: China Telecom (AS4134), China Unicom (AS4837), and China Mobile (AS9808). These three operators hold exclusive rights to international gateway capacity, meaning all traffic entering or leaving China passes through their border routers. There is no neutral open IX market comparable to DE-CIX or AMS-IX — domestic peering occurs through state-managed exchange points in Beijing and Shanghai rather than through independent, carrier-neutral facilities.

The Great Firewall (GFW) operates at the international gateway level, filtering and blocking traffic based on IP, SNI, and deep packet inspection. BGP routes announced inside China are not affected by the GFW for domestic paths, but any traffic destined for or arriving from non-Chinese IP space crosses inspection points at each carrier's border. This means latency measurements from inside China to foreign destinations include not only geographic RTT but also any queuing or inspection delay at the border routers.

Our probe node is located in Hohhot, Inner Mongolia, running on Alibaba Cloud infrastructure (AS37963). Hohhot has become one of China's largest data center hubs due to cold climate reducing cooling costs and access to low-cost coal and wind electricity. Alibaba, China Telecom, and China Mobile all operate hyperscale facilities in the region. Hohhot connects to the rest of the Chinese backbone via China Telecom and Unicom long-haul fiber running east toward Beijing and south toward Shanghai.

International latency from China reflects both geography and the GFW border transit. Hohhot to Frankfurt runs approximately 170–195 ms over well-routed paths. Hohhot to London is around 180–200 ms. Hohhot to Los Angeles sits around 130–155 ms, as trans-Pacific cable capacity is better developed than China-Europe terrestrial routes. Within the Asia-Pacific region, Hohhot to Tokyo is approximately 60–80 ms and to Singapore around 90–110 ms. These figures vary by which state carrier handles the international segment.

Results from our Alibaba Cloud node in Hohhot reflect what a server looks like from inside Chinese state carrier infrastructure, specifically through AS37963 which peers with all three national carriers domestically. For sites targeting Chinese users, this is a meaningful test location — it shows whether your server is reachable from inside China, what latency Chinese users experience, and whether the GFW is affecting connectivity to your domain or IP range.