Apple Extreme connected to devices but loses internet

I would recommend that you start by contacting your ISP and have them perform a "line check" to your modem. If they provided the modem, and it is over 3 years old, have them replace it. If they determine that everything is ok (typical), then connect your MacBook Air directly to the modem via Ethernet (if you have the appropriate cable for your Air). Try this connection for a day or two to see if it can maintain a solid connection with your Internet service.

Please post back your results.

I actually have a motorola top end modem that i purchased as an approved device by TWC

Which exact model of the Motorola modem do you have? For example, the SB6141 has been known to be incompatible with the AirPort base stations. Don't get me wrong, the SB6141 modem is a fine modem, it's just does not play well with the AirPorts. If this is what TWC provided you, then that may be the problem.

I'm having this exact same issue with a newly purchased Airport. iPhone, iPad, MacBook, Apple TV all stay connected to the Airport but Internet keeps going in and out. I've repeatedly tested with a computer connected directly to the modem and speeds are brilliant via Comcast but when connected to Wifi on the Airport, internet disconnects constantly. When connected speeds vary from exceptional to dial-up.

I've factory reset the modem several times, the Airport several times, set up a Static IP address directly, tried everything I can find online but no results.

Hope you find an answer!

Unfortunately, there is no definitive list of which modems work "best" with the AirPorts. I typically go with Cisco, but you may want to limit your choices by their rated bandwidth speeds that they support. If you are getting over 100 Mbps service from TW, then you want to go with a modem that can support that.

I believe LaPastenague has created a post in this forum on a number of modems. Just do a search and you should find it.

I've used both the Netgear CMD-31T and the Zoom 5341J with TWC for a few years with flawless results. Basically, I rotate the modems about every few months......just to keep things interesting.

My wife likes the Netgear better because it is white and matches the AirPort Extreme and the Netgear switch that it sits next to on my desk. I like the lights better on the Zoom, which is black.

I did try the Motorola SB6141 a few years back as well, and despite working with 3 different samples, none would hold a connection for more than a few hours. I had always used Motorola before in the past with very nice results, so it was the natural choice at the time....and the SB6141 seemed to be the favorite of reviewers at the time as well.

As you might imagine, TWC blamed the Apple router for the issues.....and Apple blamed the Motorola modem. Both a good products, but they just don't work well together for some users. Like all issues, some users report that the SB6141 works fine for them with their Apple router.