server_name _; and default_server on the listen configuration are what you are looking for.
Example:
server {
listen 80 default_server;
server_name _;
root /var/www/default; (or wherever)
}
server_name _; and default_server on the listen configuration are what you are looking for.
Example:
server {
listen 80 default_server;
server_name _;
root /var/www/default; (or wherever)
}