Dynamic cdn selection & geolocation for heavy dmg downloads?

General
1

Hi everyone,

I am currently optimizing the distribution pipeline for a media tool that I am hosting. We rely on IPinfo for location detection and automatic redirection to the closest regional mirror for fast download times.

Recently, I have been testing the process for mac capcut users in particular (the DMG file is rather large), and I have noticed some inconsistencies. For users on certain residential ISPs in Southeast Asia, our system, which relies on the IPinfo API, sometimes incorrectly identifies the country code, which then falls back to our US-East server instead of the Singapore mirror.

This causes a couple of related problems that I would like the community to help me consider:

Anycast vs. Unicast Detection: Do any of you use the is_anycast flag to modify how you handle regional redirection for software downloads? I am wondering if anycast IP addresses are causing our logic to fall back to a secondary location.

Accuracy for Residential Proxies: I have noticed that some users downloading mac capcut may be behind corporate VPNs or residential proxies. Is there a “best practice” for when to rely on the country field versus the privacy data to avoid sending a user to a high-latency mirror?

Caching Logic: For those of you hosting large binaries, how long are you caching the IP lookup results on the client-side? I don’t want to blow through my API limit, but I also don’t want to leave a user “stuck” on a slow mirror if their IP changes to a different region.

I’m absolutely loving the speed of the API, but I want to make sure the mac capcut installation process is as smooth as possible no matter what region the user is logging in from. If anyone has a code snippet for dealing with “uncertain” geolocations in a CDN redirect script, I’d love to see it!

2

Hi Nina,

Thank you for posting in the community! We are happy to see you here.

For users on certain residential ISPs in Southeast Asia, our system sometimes incorrectly identifies the country code, which then falls back to our US-East server instead of the Singapore mirror.

Could you share a few example IPs? I would love to investigate this.

Do any of you use the is_anycast flag to modify how you handle regional redirection for software downloads?

The anycast flag is available in our paid tier: IPinfo Core API | IPinfo.io

If you are using the free Lite API, the anycast flag is not available.

Is there a “best practice” for when to rely on the country field versus the privacy data to avoid sending a user to a high-latency mirror?

Good point. When a user is connected through a VPN, all their traffic flows through the VPN server. IPinfo returns the geolocation of that VPN server’s IP address, since we do not have visibility into the end user’s actual IP. In that case, routing to the mirror closest to the VPN server’s location is technically the correct behavior.

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The user is in Africa. Their VPN server is near Australia. File Server Mirror #1 is also near Australia, and File Server Mirror #2 is in southern Africa.

The diagram shows that routing to the mirror closest to the VPN server (Mirror #1, near Australia) is the correct behavior — because all packets travel through the VPN tunnel from the user → VPN server → mirror. The physical proximity of the user to Mirror #2 is irrelevant, since traffic cannot go directly from the file server to the user, bypassing the VPN.

If you want to detect VPN or proxy usage and handle those users differently — for example, skipping mirror optimization entirely — that would require our privacy detection data, which is available in the paid tier.

I don’t want to blow through my API limit, but I also don’t want to leave a user “stuck” on a slow mirror if their IP changes.

Since you need fresh country code data per request, I would recommend not caching. The IPinfo Lite API supports truly unlimited lookups at no cost, so there is no need to worry about hitting a quota. Caching is most useful when you are making repeated identical lookups for the same IP in a short period — which is less common in a download flow where each user typically hits the endpoint once.

Please check out the docs for the Lite API service:

:link: IPinfo Lite API | IPinfo.io