Hello, when I set a default vhosts with server_name _; it doesn't work. Here the example file:
server {
listen 80;
server_name _ ; # underdash means for all hosts

location / {
root /var/www/html;
index index.html index.htm;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /var/www/html;
}
}