HI
I m Doing a Cable net business.I have setup a redhatlinux 9.0 as a server which have two Nic installed fisrt is for dsl ip 192.168.0.1 and second Nic is for client output which ip is 10.0.0.1 problem is that one of my client set the 10.0.0.1 on his computer and my all network traffic blocked.That cleint is too sharp.i m wonder of linux that how can linux allow the user to set his own Nic ip whereas in Windows Xp environment no user can set their server ip when anyone try the messege come that this ip is already assingned to another computer while in linux this eroor is not come and user can easily set the server ip on his computer.what can i do.why the linux is weak or another problem plz help me.

Thanks