Someone was complaining about a network I maintain, and said that my network is bad. However we found the application was depending on the following:
root@obproxy:~# wget -SHO - https://get.geojs.io/v1/ip/geo.json
--2023-01-08 15:59:37-- https://get.geojs.io/v1/ip/geo.json
Resolving get.geojs.io (get.geojs.io)... 2606:4700:20::681a:64, 2606:4700:20::681a:164, 2606:4700:20::ac43:46e9, ...
Connecting to get.geojs.io (get.geojs.io)|2606:4700:20::681a:64|:443... connected.
HTTP request sent, awaiting response...
HTTP/1.1 500 Internal Server Error
Date: Sun, 08 Jan 2023 15:59:38 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
x-request-id: f4ffd7e64972ea270b7f89f527228b92-AMS
strict-transport-security: max-age=15552000; includeSubDomains; preload
access-control-allow-origin: *
access-control-allow-methods: GET
pragma: no-cache
Cache-Control: no-store, no-cache, must-revalidate, private, max-age=0
x-geojs-location: AMS
CF-Cache-Status: DYNAMIC
Report-To: {"endpoints":[{"url":"https:\\/\\/a.nel.cloudflare.com\\/report\\/v3?s=yBx8lTgrKvBcwNOrOJa8Dyr9P49F7WBpMu34EOAELjcKk7pomCyk%2B96oL%2F%2BCv21%2FAF6LQnoHLKJ6eQxjsVQYdCc9e1YW0vXFYhIWsNrBn6%2BqS8Y9RW45HF6%2BPOR1QAUK0Zl%2F1Sd63Yniqg%3D%3D"}],"group":"cf-nel","max_age":604800}
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
X-Content-Type-Options: nosniff
Server: cloudflare
CF-RAY: 78662438fb850eaf-AMS
alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400
2023-01-08 15:59:39 ERROR 500: Internal Server Error.
Since the 500 means that cloudflare received an error from the application I assume the application breaks for certain source ip's.
I would love to tell you the source ip/range, but I'd rather not invite an army of port scanners on that network.
I assume the 500 would be traceable in the logs.
Thank you for looking at it.
In the mean time I hope we can ask the software provider to make that request optional.