GeoDNS Checker
Resolve a domain from probes on every continent and group the answers to reveal GeoDNS, CDN and global load-balancer steering: see exactly which addresses users in each region are sent to.
About GeoDNS Checker
Most domains resolve to the same addresses everywhere on earth. Large ones deliberately do not. CDNs, global load balancers and GeoDNS services answer the same query differently depending on where the asking resolver is, so that a user in Brazil is sent to a Brazilian edge node and a user in Japan to a Japanese one. From a single vantage point this steering is completely invisible: you see one answer and have no way of knowing it is not the answer everyone else gets. This tool resolves the name from probes across six continents, groups identical answer sets together, and tells you plainly whether the result varies.
When it does vary, each group in the results is one set of addresses being handed to one part of the world, with the cities that received it listed underneath. That is the fastest way to confirm a CDN is configured as intended, to check that a new regional point of presence is actually being advertised to the region it was built for, and to catch the classic failure where a supposedly global service quietly steers every user to a single origin because a health check has taken the other edges out of rotation. A tool that resolves from one place will report that situation as perfectly healthy.
Steering is done on the address of the recursive resolver making the query, not the end user's, which is why it can go wrong in ways worth checking. A user in Portugal whose device is configured with a resolver anycast to a node in Ireland may be steered to Irish infrastructure; EDNS Client Subnet, defined in RFC 7871, exists to pass a truncated client prefix along so the authoritative server can decide correctly, but not every resolver sends it and not every authoritative server honours it. This is also why the resolver each probe used is shown in the results: it is part of the explanation for the answer it received.
Do not confuse geographic steering with anycast. With anycast the same IP address is announced from many locations and routing decides which one you reach, so the DNS answer is identical worldwide and this tool will correctly report no variation even though users are served by different machines. GeoDNS changes the answer itself. Both are legitimate designs and large services frequently combine them. Measurements run on the Globalping open probe network through our EU-hosted API, with a ten-minute cache; nothing is shared with third-party trackers.
How to use it
- 1Enter the domain name you want to inspect, for example example.eu.
- 2Choose the record type - A is the usual choice for geographic steering, AAAA for IPv6, CNAME to see which edge hostname is handed out.
- 3Select Resolve worldwide; the query runs from probes on every continent at once.
- 4Read the banner: it states plainly whether the answers vary by region, and how many distinct answer sets were seen.
- 5Expand each group to see the exact addresses and which cities received them, and check the resolver column to understand any surprise.
Common use cases
- -Confirming a CDN or global load balancer is steering each region to the intended edge, which a single-location check cannot show.
- -Catching the failure where every region is silently sent to one origin because health checks removed the other edges.
- -Verifying that a newly launched regional point of presence is actually being advertised to that region.
- -Understanding why users in one country reach a different address, and whether their resolver rather than their location is the reason.
- -Distinguishing genuine GeoDNS steering from anycast, which returns the same address worldwide.
Frequently asked questions
- What is GeoDNS?
- GeoDNS is an authoritative DNS configuration that returns different records depending on where the query appears to come from, so users are directed to infrastructure near them. It is the mechanism behind most CDN and global load-balancing products. Because the decision happens at resolution time, the only way to observe it is to resolve the name from several places at once.
- My domain returns the same answer everywhere. Is something wrong?
- No. A single global answer set is normal and correct for the large majority of domains, including many that sit behind a CDN, because the CDN may use anycast rather than DNS steering. Uniform answers only indicate a problem if you specifically configured regional steering and expected to see it.
- Why does the answer depend on the resolver rather than on the user?
- Because the authoritative server only sees the address of the recursive resolver that queried it. EDNS Client Subnet (RFC 7871) lets a resolver pass along a truncated prefix of the real client so steering can be more accurate, but support is not universal. This is why a user can be sent to infrastructure near their resolver rather than near themselves, and why the resolver used is shown alongside each answer here.
- How is this different from a DNS propagation check?
- A propagation check asks many public resolvers whether they have seen your record yet, which is about how a change has spread and how caches have expired. This tool asks whether the answer itself is deliberately different by region. Propagation is about time; GeoDNS is about place. Use the propagation checker after editing a record, and this one to understand steering.