This makes it so that your ISP doesn't see the actual name of the server/site you're communicating with, only the IP address. Without Encrypted Hello they're able to see both.
I would think that an IP address tells you the domain name by doing a simple DNS lookup.
In many cases you can, but there's never a guarantee that a given IP address will have reverse DNS records configured for resolve it into. On top of that, if it's a major site it's likely hosted behind a content delivery network that may a share a single IP address across thousands or even millions of completely unrelated servers. Cloudflare does some pretty interesting stuff with that approach: https://blog.cloudflare.com/cloudflare-servers-dont-own-ips-anymore/
edit: bad at typing
This makes it so that your ISP doesn't see the actual name of the server/site you're communicating with, only the IP address. Without Encrypted Hello they're able to see both.
I would think that an IP address tells you the domain name by doing a simple DNS lookup.
In many cases you can, but there's never a guarantee that a given IP address will have reverse DNS records configured for resolve it into. On top of that, if it's a major site it's likely hosted behind a content delivery network that may a share a single IP address across thousands or even millions of completely unrelated servers. Cloudflare does some pretty interesting stuff with that approach: https://blog.cloudflare.com/cloudflare-servers-dont-own-ips-anymore/ edit: bad at typing