I want nginx/0.7.6 (on debian, i.e. with config files in /etc/nginx/sites-enabled/) to serve a site on exactly one subdomain (indicated by the Host header) and nothing on all others. But it staunchly ignores my server_name settings?!

In sites-enabled/sub.domain:

server {
  listen 80;
  server_name sub.domain;
  location / { … }
}

Adding a sites-enabled/00-default with

server {
  listen 80;
  return 444;
}

Does nothing (I guess it just matches requests with no Host?)

server {
  listen 80;
  server_name *.domain;
  return 444;
}

Does prevent Host: domain requests from giving results for Host: sub.domain, but still treats Host: arbitrary as Host: sub-domain.

The, to my eyes, obvious solution isn't accepted:

server {
  listen 80;
  server_name *;
  return 444;
}

Neither is

server {
  listen 80 default_server;
  return 444;
}

Since order seems to be important: renaming 00-default to zz-default, which, if sorted, places it last, doesn't change anything. But debian's main config just includes *, so I guess they could be included in some arbitrary file-system defined order?

This returns no content when Host: is not sub.domain as expected, but still returns the content when Host is completely missing. I thought the first block should handle exactly that case!? Is it because it's the first block?

server {
  listen 80;
  return 444;
}
server {
  listen 80;
  server_name ~^.*$;
  return 444;
}