Your IP Geolocation Tool Is Lying to You!

Think about it: when you paste your IP into a “What’s My Location?” tool, it often shows your city, country, and ISP. It looks accurate. That’s because residential IPs from ISPs are usually quite reliable in pinpointing your general location.

But when the IP comes from cloud giants like AWS, Google Cloud, Microsoft Azure, Cloudflare, Fastly, Akamai, etc.. the story changes.

These providers often use Anycast routing combined with BGP announcements from multiple global points of presence. Even though you're seeing one IP address, it might be served from anywhere in the world, depending on which path is closest to you from a networking perspective, not necessarily where the server physically is.

This breaks the assumption that an IP address equals a fixed location. If you’re relying on that data for fraud detection, compliance, geo-targeting, or analytics, you could be working with completely misleading information.

The technical twist: Anycast, BGP & multiple regions

What is Anycast?

• Anycast is a network design technique where the same IP address is announced (via BGP) from multiple geographically distributed nodes. 

• When your device sends packets to that IP, the routers will direct your traffic to the “best” copy of that IP not based purely on physical distance, but based on routing costs (AS path length, prefix policies, link metrics, etc.).

• Thus, two users in different countries might reach different servers, even though the IP is “the same.” 

Why GeoIP fails in the presence of Anycast

• Many geolocation databases assume that an IP is tied to one fixed place and thus store a “best guess” lat/long or city for that IP. But if the IP is anycast, that guess may reflect one of the nodes (or even the “origin” registration), not the one actually serving your traffic.

• The same IP might at times be served from Paris, at others from New York, depending on network load, failures, peering changes, or routing table updates. 

• Some geo‑databases, when they detect an IP is anycast, will default to using the WHOIS-registration location (where the IP block is officially registered) rather than where the traffic is served at any moment. 

• Because ISPs and networks change peering or routing policies, the “best path” changes. That means your location as seen by a geo service can change over time, even though your physical location hasn’t.

• Ultimately, the geo guess might be off by hundreds or thousands of kilometers sometimes even to a different country. 

So yes, it’s possible that every user (yourself included) wrongly believes the geolocation they see is “correct,” when in fact it’s not.

How you can try to find the “actual” geo location (or at least get closer to it)

There is no guaranteed magic bullet, but network diagnostics + routing insight can help you triangulate a more plausible location.

1. Traceroute / Tracert / MTR
   Run a traceroute to the IP in question. Look at the intermediate hops, especially the near‑final ones. Many routers include hints in their reverse DNS names (e.g. “las‑nyc‑core”, “lon‑dc1”) or ASN tags. These hints may help you see which city or network you’re reaching.
   That path gives you a clue about which ISP / which network is delivering the traffic to you.

2. Look at ASN and upstream network
   Do a WHOIS or BGP lookup of the IP’s ASN / prefix. That gives you which network “owns” the block. Then ask: Where is that ISP / backbone / edge network located? Sometimes the ISP is local to your country, sometimes the block is part of an international CDN network, etc.

3. Observe latency / RTT values
   If you ping (or use latency probes) from various vantage points, you may see latency patterns consistent with a region. (E.g. you see 20 ms to some routers in Europe, 200 ms to ones in US, etc.) That helps you guess which region is serving you.

4. Check BGP advertisements nearest your ISP
   The BGP route that your own ISP picks for that prefix is the one that determines which anycast node you reach. So the “geo” that matters is the BGP advertisement closest to your ISP. If you had access to your ISP’s BGP routing table or peering details, you could see which path they chose and thus infer which node (region) is active. In other words, the “closest BGP hop” to your ISP is your effective geolocation.

5. Use multiple geolocation databases and compare
   Query multiple sources (MaxMind, IPinfo, DB-IP, etc.) and see where they differ. If one reports the registered location, another reports a city far away, the divergence itself is a red flag for inaccuracy.

In practice, by combining traceroutes, ASN insight, and latency, you can often narrow down a “likely region” better than blindly trusting a single GeoIP lookup.

Why geo‑blocking using IP geolocation is tricky (and often flawed)

Many services try to block traffic from certain countries (for regulation, licensing, compliance, etc.). But relying purely on GeoIP databases has pitfalls:

• If an IP is anycast, users in a disallowed country might appear (via routing quirks) to come from an allowed region or vice versa.

• Unless the Regional Internet Registries (RIRs) explicitly state that a particular IP range is solely for one region and cannot be used elsewhere, there is always ambiguity.

• Attackers or proxies might reroute or “bounce” through networks that make them appear to be from a benign country, even if they are not.

• Any errors in geo databases can lead to false positives (blocking legit users) or false negatives (letting unwanted users in).

• Because routing policies can change, blocking based on a “fixed geolocation” may break over time as IPs shift in routing.

Therefore, geo-blocking should not rely on a single GeoIP service. It's safer to combine methods (e.g. IP + user information + network heuristics) or use more robust techniques (VPN/proxy detection, behavioral profiling, etc.).

The bottom line & key takeaway

• The intuitive belief “my IP maps to this city/country” is almost always naive.

• Anycast + BGP routing means an IP can effectively exist in multiple places, and which one you hit depends on network topology and routing policies.

• The “true” geo location is the BGP route your ISP picks to reach that IP, so the advertisement closest to your ISP matters most.

• To get closer to reality, use traceroutes, ASN lookups, latency analysis, multiple databases, and domain name hints.

• Be wary of pure geo-based blocking it can backfire unless you layer additional logic.