We have a popular puzzle game on the AppStore. We notice some Virgin Media customers cannot connect to our content delivery network. The connection fails. Customers on BT are fine.
We use both cloudflare and CDN77 for speeding up access to game assets. I have asked some customers to do a DNS lookup on our domains, and access a test URL, but what is interesting is the DNS lookup does not return the correct answer for our servers. For example the correct response should be:
geo.sparklecdn.com has address 184.108.40.206 geo.sparklecdn.com has address 220.127.116.11
But customers on Virgin Media get this:
geo.sparklecdn.com has address 18.104.22.168
In fact they get the same IP (22.214.171.124) for all our endpoints. It resolves to lang-sspiprxy.network.virginmedia.net
The problem only seems to have occured since iOS13 was released with stricter requirements in terms of SSL certificates. Does anyone know what sspiprxy.network.virginmedia.net is, and why we can't access our CDN through it? For example this URL is blocked: