TC , set up as my router, dropped off list of local networks,nowhere to be found. Have an ATT modem that is wired to the TC. How do I reinstate it to the list ?

Tesserax appears to be offline today, so I will answer.

He did provide you with the detailed steps to reset your Time Capsule and set it up again....and we asked where in the process that you were getting stuck....to try to fix things. We could not seem to get a clear response from you to work through this snag.

There are different ways to skin a cat, so if you want to try another approach that basically does the same thing, the steps are listed and illustrated below. I have added a few details as well.

Make sure that an Ethernet cable connects from one off the LAN <--> Ethernet ports on the ATT modem/router (there are probably four of them....choose any one that you wish) to the WAN "O" port on the Time Capsule (TC).

Power up the TC, if it is not already on, and leave it on for a few minutes

Hold in the reset button on the back of the TC for 7-8 seconds. The amber light on the TC will blink quickly during this time. Release the reset button after the hold period and allow a full minute for the TC to restart to a slow, blinking amber light status

Click on the WiFi menu at the top of your Mac's screen and look for a listing of New AirPort Base Station. Just below that, click on Time Capsule, or it might read AirPort Time Capsule.

When you click on AirPort Time Capsule, that will start up the AirPort Utility setup "wizard". It will take a few seconds to analyze the network and then display a screen that looks similar to the illustration below, except that you will see a Time Capsule pictured.

Network Name......Type in the same wireless network name that you used before

Base Station Name....Type in a device name for the Time Capsule

Password.....Type in the same wireless password that your network used before

Verify....Type in the same password again to confirm

Click Next

The setup wizard will set things up for you automatically. When you see the message of Setup Complete, click Done.

Now click on the WiFi menu again at the top of your Mac's screen and then select the name of the Time Capsule, and enter the password if required.

If you want to use the Time Capsule wireless network, simply do not connect to the ATT WiFi network. If you don't plan to use the ATT wireless at all, ATT Support can tell you how to turn off the broadcast of the ATT network, so the only WiFi network that you will see will be from the Time Capsule.

Have an ATT modem that is wired to the TC

Your ATT "modem" is very likely a modem/router or gateway. This is a device that combines a modem and a router in one package. If you then try to set up the TC as a router, you have a situation where there are two devices on the same network both trying to act as routers.

This makes things a lot more complicated, and there are performance issues to consider, even if you can get the double router set up to work.

Can you please post back with the make and model number of the ATT device that you call your "modem"? Once we know what we are dealing with, we can provide possible solutions.

This is a ATT model #BGW210 device

Thanks for the info. I have not worked with this particular modem/router or gateway, but it appears to be pretty much a standard issue product similar to devices that most providers supply to their customers.

This TC was set up previously for at least a year subservient to the ATT device.

And this is the way that the TC should be set up in the future as well. Another way to say the same thing.....your ATT modem/router will always be "in charge" of your network, even though you might be using the Time Capsule to provide your wireless network. You can likely turn off the WiFi function of the ATT modem/router if you don't want to have two WiFi networks, but the ATT device will still be your main router if you do this.

I have operated for the last 4-5 years in that mode with previous TCs and ATT devices together

This is fine if things are working OK, unless you simply don't want to use the ATT WiFi network, in which case it would make sense to look into turning off the WiFi function of the ATT modem/router. Up until now, the Time Capsule has been operating in what is known as "Bridge Mode" to work correctly with your ATT modem/router.

I was told that the suggested preference was to use the TC as my router supposedly because it is more adapted to and efficient with my apple products.

I'm sure they meant well, but whoever told you this was apparently not aware that you had an ATT modem/router or gateway that you must use as the main router in control of your network.

In theory, it is likely possible to configure the Time Capsule as a second router on your network, but the disadvantages of doing this....even if it appears to work....far outweigh the advantages of setting up the Time Capsule as a second router for the network. Reason.....you will have a basic network error known as Double NAT with a two router setup. Double NAT can create any number of issues on a network, not the least of which are slower connections and loss of connections, as well as slow (or no) browsing on some websites.

Another way to say the same thing would be to state that if you want the Time Capsule to act as the main router on your network, you will need to replace the ATT modem/router with a simple modem.....and ATT does not offer this type of option. You must use the modem/router or gateway that ATT provides.

So, I'm not sure how you want to proceed at this point.

Tesserax suggested a complete power cycle of the network. Did you try this? What were the results?

Since Tesserax responded to you first, to avoid confusion, I'm going to wait to see how he advises based on your results and your response.

The link I provided is a good starting point to "revive" a non-functional network. It takes you through the steps of powering-down, and then powering-up your networking devices (in order) to re-establish communications between them. Please give it a try and report back your results.

I was told that the suggested preference was to use the TC as my router supposedly because it is more adapted to and efficient with my apple products.

I tried to explain previously that whoever told you this was probably trying to help.....but they also were likely not aware that ATT will not really allow you to do this. It is unfortunate that the advice that you received has basically removed your TC from your network.

I also asked if you tried the procedure that Tesserax had previously suggested. It appears that you have not done this. The procedure walks you through the process of resetting the TC and setting it up again, which is what you need to do if you want to get the TC working again with your ATT modem/router, if that is your goal.

As Tesserax has asked, please report on your results. If you are getting stuck, please provide more details so that Tesserax can understand where it is that you need assistance.

Although the TC is an Apple product and works well with other Apple products those other Apple devices do NOT require a that the wireless router come from Apple. Another thing to consider. Apple has not updated the TC in over 5 years ... and they, may or may not, going forward. Most typical consumer-grade networking hardware lasts between 3-5 years so your will be very near the end of its useful life ... and maybe why it has "dropped off."

The new modem/wireless router (or gateway device) that AT&T has provided you may be much more capable than your TC ... expect for being a Time Machine backup destination ... and there are plenty of alternatives for what to use for destinations for TM backups.

Unless you require additional wireless coverage at your home, you can safely "retire" your TC and just use the AT&T-provided gateway to provide your Wi-Fi network.

Start here: AirPort - Complete Power Recycle. Then post back your results.