Bagaimana cara untuk IP canonicalization dan URL canonicalization di nginx?

kalau di buka http://111.222.333.444 forward ke http://www.domain.com

kalau buka http://domain.com forward ke http://www.domain.com

ini default.conf saya:
------------------------begin------------------
server {
listen 80;
server_name domain.com www.domain.com;
root /home/user/www/domain.com/public_html;
index index.php index.html;
include /etc/nginx/default.d/*.conf;

location / {
try_files $uri/ $uri /index.php?mod=$uri&$args;
}

error_page 404 /404.php;

location ~ \.php$ {
include /etc/nginx/fastcgi_params;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
}

rewrite ......
dst..........
}
----------------------------end-----------------------

terima kasih