i want to use limit_conn to let all remote address user maximum 1 connection. I also want to let list of private port have unlimit connection. how do i do that?

here is my sample conf:
[code]
limit_zone remote_addr $binary_remote_addr 10m;

location / {
listen 80;
server_name download.example.com;

root /var/www/html1/;

# limit connection
limit_conn remote_addr 2;
limit_rate 10k;
}
[/code]