192.168.1.254 Login

No... you are already connected to the gateway if you see the main page... a non connected device would not have access.

Cannot make any changes without the DAC (device access code) which is listed on the side of the gateway... this only individual devices can connect and access the main page if they already have the information.

If wish to place a layer between you and other devices... create a guest network and only provide that information to devices. Then someone on those devices cannot login to the gateway.

From memory, I believe the guest network is restricted to the 2.4Ghz b/g/n wireless network (slower speeds).

But on the Router main page (which is "Device" tab) that comes up after entering 192.168.1.254 it shows my AT&T "Network Name (SSID)"  and the Network Authentication "Password".  

Are these AT&T Network Login information supposed to be shown or visible on this page? 

I need to get more dial time on my phone [EDITED per Community Guidelines]

@kmart5115 Not sure why you posted your phone number on a year old totally unrelated thread but this is a public forum, suggest you remove it unless you want more spam calls.