I have a home network comprising:
1 x Sky Broadband Router (Sagem)
1 x Personal PC 64bit Win7 (mine) which maintains overall control of the network & content of the NAS
1 x NAS
2 x Sky HD boxes with Anytime+ which require internet access
1 x Xbox 360
1 x 3D TV with Netcast & DNLA (Over which my wife maintains complete & strict control

)
3 x Android mobile phones
3 x Children's PC's (only 2 of them are wireless capable laptops, 2x Win7 & 1x Vista)
The TV, Xbox360, Sky HD boxes & the children's computers all are connected via 200mbps powerline LAN adapters.
I work away from home for long periods & my wife is a complete technophobe.
My children tend to abuse the privilege of internet access while I am working away, staying awake until stupid o'clock on school nights etc.
My question is simple: Is there any way I can limit the amount of time the children have access to the internet? ie. automatically deny access between say 10pm & 6am. Ideally I would like to only restrict certain IP addresses, obviously the children's. While not affecting any of the other attached devices or PC's.
What makes things more complicated for me is the dynamic IP assignments which, due to the limitations of the SKY supplied router & equipment I am not able or allowed to change. Therefore use of MAC addresses to ID the children's PC's would be preferable. Remote access control while I'm working away would also be very useful too.
My intention is that access to the NAS will remain unrestricted as I have complete control over it's content & even my wife can manage to turn that off & on. Fortunately it's physically located where the children don't have easy access even when I'm away.
I don't need advice concerning restricting web sites, messagng or P2P etc. That is quite straight forward. My children are quite savvy teenagers. Need I say more?
Of course ideally freeware software would be good.
I tried PRTG but found it to be way too complicated & not really suitable for my simple needs.
Personally I feel that there is a gap in the market here. Home networks are much more prevalent now & some simple to use good GUI software which does the above would probably be well received by most parents.
Any feasible suggestions would be greatly appreciated...
Thanks in advance...