A story about bypassing air Canada's in-flight network restrictions

tldr; the wifi's access restrictions still allowed DNS so they set up a vpn on the dns port

I haven't used iodine, but this seems simpler. Iodine wraps requests with actual DNS requests. In this case that wasn't needed, because port 53 wasn't filtered at all. So all they needed was a simple proxy on port 53.

> We affirm our strict adherence to all relevant regulations and service terms throughout this project.

Except if you bypassed payment and used the service in a manner that was not intended, most likely you were by definition not undertaking "strict adherance" to service terms ?

Limiting availability of third party services based on local service provider fee can only be done 100% reliably on a service side through an agreement with that provider, i.e. WhatsApp needs to disable certain functions to users coming from certain dedicated links or IP ranges, or even based on live user status metadata. There's an obvious size mismatch, and lack of incentive to implement compartmentalisation only needed for some other company. It also creates enormous shared responsibility and potential circular finger pointing clown shows, all for relatively tiny number of affected paying users.

Therefore, it is either done with least amount of work that is “good enough”, and can be done on a cheapest router (rate limit to the absolute minimum, ban connections to ports 80 and 443, maybe cut the traffic to most stable IP ranges of biggest services, and regular person is going to state that “nothing else works”), or trough very extensive commercial DPI with lots of guessing and ad-hoc rules (if this feature is important for the income, and many will try to game the system). So it's either going to be as simple as in this example, or you'll compete with the global army of detection rule authors.

Though I do like the wink-wink, nudge-nudge choice of proxy software.

If a ping to a specific IP times out, I wouldn't say the IP is blocked. It could be that ICMP specifically is blocked, following some network rules on the firewall. This is pretty common in entreprise networks to not allow endpoint discovery. I could be missing something and happy to be corrected here, but I was surprised to read that.