Earlier quoted context omitted.
Its always DNS first and everyone says "lol, just change your DNS" and then they start doing real blocks. Optus in Australia did an IP level block of 4chan recently.
How? 4chan use Cloudflare. They don't have a dedicated IP, do they? I would be surprised if Optus actually managed to do SNI filtering for the entire country without screwing it up. Edit: Huh, seems like they do have a dedicated IP. At least both Robtex and Securitytrails report them as the only tenant on their IP. But you can /etc/hosts 4chan.org to a different Cloudflare IP, and CF will still SNI-route it to the re…
I have also written how the site can try to bypass the blocking: https://news.ycombinator.com/item?id=19552689