I recently tried to set up the following server block:
server { listen 80 default_server; listen [::]:80 default_server; listen 443 ssl default_server; # this and listen [::]:443 ssl default_server; # this server_name _; return 404; } This works perfectly for http connections. But every connection to other ssl hosts fails if I activate this block. Chrome for example outputs ERR_SSL_PROTOCOL_ERROR. If I comment-out the lines marked with #this, then it works again. In my opinion, this seems to be a bug. Another user has stated the same problem in a comment in this post.