How to install a Web Proxy ?

RouterOS General
1

I have Mikrotik 2.9.6 running on a PC with a Compactflash of 128 MBytes, and all is working fine.

This PC has two ethernet ports and this is the main router of my WISP. Here is where I do NAT and bandwidth control.

Now I have more than 150 customers and is time to have a transparent Web Proxy running on that machine.

What do I need to run a Web Proxy in that machine ?. I suppose that I need a hard disk. But I would like to know what are the general steps to set up the Mikrotik Web Proxy service.

Thanks