Example wordpress vhost for aegir box, also see https://gist.github.com/BrianGilbert/6227135

wordpress-vhost.conf

server {
  include     /var/aegir/config/includes/fastcgi_params.conf;
  limit_conn  gulag 32;  # like mod_evasive - this allows max 32 simultaneous connections from one IP address
  listen      *:80;
  server_name wordpress.domain.name;
  root /var/www/siteroot;

  # Extra configuration from modules:
  include  /var/aegir/config/includes/nginx_wp_include.conf;
}