Problem
I have an internet connection that I want to split between four separate networks. My requirements are:
I need to be able to monitor the amount of bandwidth and data being used by each network, and notify or control as necessary.
The four networks should only be able to connect to the internet, not each other.
My parents need to be able to operate it, so it needs a simple, preferably Windows-based GUI.
Progress so far
Server
I have a mini-ITX server with six Gigabit ethernet ports - one for the ethernet internet connection, one for each of the four networks, and one for remote access to the server for administration.
Bandwidth control
I spent a long time researching solutions here. The majority of the control systems/software I found could control bandwidth usage via QOS, but could not monitor or control the amount of data being used. Eventually I found the SoftPerfect Bandwidth Manager, which has everything I need in terms of monitoring and control - per-interface quota management, usage statistics, a web interface for checking usage, and email notifications when quotas are exceeded. It is also Windows-based and has a simple GUI.
Internet sharing
This is where I am having issues. I am currently using Windows XP Pro SP2 for the server (yes, I know this is far from ideal, but it's the only spare Windows OS I currently have). I can't use the built-in Internet Connection Sharing for several reasons:
The upstream internet router has an IP of 192.168.0.1 which ICS clashes with, and I cannot change the router settings.
ICS can only share an internet connection with a single interface, but I have four. I have tried bridging the four network cards, but then the Bandwidth Manager cannot see the four individual interfaces - it only sees the bridge.
I have tried setting up Dual DHCP DNS server (and am having issues getting DHCP offers to be received by clients), but that would still require gateway software of some sort, which I have been unable to find.
My current attempt is to use OpenVPN, with a server for the internet NIC and a separate client for each of the four networks. My thought is that I could bridge the OpenVPN TAP devices to each NIC, meaning that the Bandwidth Manager would control traffic from the bridge instead of the interface. I have not made much progress here though - I've never used OpenVPN before.
Questions
Is there a Windows software package that does everything I need? (Unlikely, I know)
Is there a Windows software package that will share internet between multiple NICs without bridging?
Are either of my about attempts feasible?
Would it help to have a newer/server version of Windows?
Is there a non-Windows alternative that is easy to use?
