I've not tested protocols that are available on iOS "out of the box" (guessing L2TP, IPSec?), but here's my two cents:
1. It differs from ISP to ISP. Right now I'm using a major ISP and I have no problems connecting to a Hetzner IP via:
- plain WG
- OpenVPN
- Shadowsocks
My mobile operator blocks OpenVPN, other methods work.
2. Time could also play a role - there seem to be "tests" about how the government could block some protocols without affecting business etc. - these happen bi-monthly and last ~2-5 days.
My friend uses a different major ISP and he reported broken Shadowsocks this week, though it started working again.
3. The endpoint also matters (obvious in hindsight). "Internal" endpoint seem to "break" very rarely, if at all. Obvious, if you consider that a lot of people need to remote into their corp nets.
1. It differs from ISP to ISP. Right now I'm using a major ISP and I have no problems connecting to a Hetzner IP via:
- plain WG
- OpenVPN
- Shadowsocks
My mobile operator blocks OpenVPN, other methods work.
2. Time could also play a role - there seem to be "tests" about how the government could block some protocols without affecting business etc. - these happen bi-monthly and last ~2-5 days. My friend uses a different major ISP and he reported broken Shadowsocks this week, though it started working again.
3. The endpoint also matters (obvious in hindsight). "Internal" endpoint seem to "break" very rarely, if at all. Obvious, if you consider that a lot of people need to remote into their corp nets.