iptables -t nat -A PREROUTING -p tcp -s 192.168.0.0/16 --dport 80 -j DNAT --to 192.168.0.1:#[port]#
These settings configure the access method to your own http proxy and server. All traffic is routed throug one single port, for both proxy and server.
Server Access Restrictions You can restrict the access to this proxy/server using a two-stage security barrier:
This is the account that restricts access to the proxy function. You probably don't want to share the proxy to the internet, so you should set the IP-Number Access Domain to a pattern that corresponds to you local intranet. The default setting should be right in most cases. If you want, you can also set a proxy account so that every proxy user must authenticate first, but this is rather unusual.