During the most recent switch of ISP, we foun that our bandwidth utilization was high, and we had to setup a transparent web proxy to cache commonly shared files. Our File/Print/Active Directory server is running Windows 2003 standard edition, and setting up any kind of proxy was convoluted, error prone and would affect the performace of the box.
I raised this on the local linux users forum, lug@linux.or.ug, where one of the members suggested that we try IP Cop (http://www.ipcop.org) which would run on an old Pentium III box. We had a PIV with 1GB RAM, and a spare network card so we were all set.
The download was amazing, 60MB, installation even more so, 10 minutes we were up and running. The green (local network) and red (ISP) network cards were recogonized and setup in a flash. The management is via a web interface so even we who were Linux challenged, had somewhere to start.
The proxy service was up and running in two clicks, configuring it to be transparent to the network browsers was just a checkbox. The ISP also provides an upstream proxy which we configured as the parent proxy sever, and now we are up and running.
The cache hits are now up to 30%, and so far at least we are saving that bandwidth.
The next challenge that we are grappling with is to configure NTOP (http://www.ntop.org) on the IPCop so that we can identify where the traffic is coming from on the internal network.
Thats a story for another day ….