A:AnswerI recommend looking on youtube for setup guide/reviews. The connection order should go from the wall > ATT modem > linksys router > computers / devices. You’ll have to configure ATT’s DNS IP addresses on the router for better performance.
A:AnswerGetting the wifi to work perfectly takes time and effort. The advertised speeds require that your devices support
MU-MIMO, which I really think they don’t since is very new technology.
A:AnswerYes it does support Dyn-DNS on the admin settings. I didn't find a section for a third party cert but a quick google search shows it may not be possible.
A:AnswerYou still need an Internet Service Provider (ISP). The purpose of this device is to take an internet signal that is coming into your house and make it available to wireless devices.