I do not know very much about linux, so I am not using what you might call the back door yet (ie etc/sysconfig/network). I do know a bit about Windows Networks (without being to boastful).
In Redhat, select start menu, select System Settings, select Network. A Network configuration screen should open.
Under tab DEVISES, select your network card so it is highlighted.
Click the EDIT button above.
- a screen should open that says Ethernet Device
At the bottom you will see Default Gateway Address
Enter 192.168.1.1 and click OK
Next Select DNS Tab
Enter The Host name of your client computer.
Enter the Primary DNS and the Secondary DNS of your internet service provider.
Again, you should be able to obtain DNS values from your Router since you already have a connection to the internet; I'm assumming through Windows.
You have to do the same thing for each client computer whether it is Windows or Linux. Getting to the proper screens is a matter of knowing the OS.
Let me know how you made out.