[John Rogers]

If I read all this correctly you only have the router that your service provider sent you and the computers are all wired with CAT5 cable? I have our house wired like that except for WIFI use on my iPhone when up stairs and about 45 feet away. If that case I have two signal boosters that run off a separate Asus router that is inside our ATT box. Here is what I did when the ATT box failed last year.
- When new ATT box came I shut everything off before connecting.
- There is one cable to the HD box in the living room, one to the secondary signal sender and ONE to my inside ASUS router.
- The inside router had to be told what the new box was after I changed it's name and password.

The inside router handles 99% of the security by disabling all MAC addresses except my PC, laptop (normally off) and iPhone. I change the password at least twice a year. and the ASUS router has an alarm should someone try to guess the password and try to get into my network.

Mainly I do not trust ATT for security.