Just stumbled across this thread. here ----> http://www.dslreports.com/forum/remark,15607820
Apparently I have an SBC "Starter Kit 4100 modem" with many security features missing / disabled . . . . figures. So I guess the "hide IP address" option is moot?
The number on the device label should tell you which you have
12A-4100-506 Starter Kit model apparently
I would be inclined to put a good full featured router between my LAN and the 4100 and set the 4100 to bridge mode.
Choose a router with good traffic controls so that the traffic for a particular PC can be limited (Parental Control).
Of course if you have a dedicated PC doing the same job then there is no real difference.
I think it is a disgrace that people are supplied devices that are crippled thus exposing them unnecessarily to the dangers of the 'baddies' out there.
If you now own that device maybe it is possible to update the firmware to enable the other features .....
In the meantime I guess you will just have to regard it as a modem, and ignore its private IP setting .....