How to configure Time Capsule without connecting to the internet box ? only for backups

I am going to throw the proverbial spanner in the works and say you can do both backups over ethernet and internet by wireless simultaneously.

The problem is your TC is now setup wrongly.

I presume your computer is going to get internet via wireless when connected in the office. So to backup you plug the TC into the ethernet.

Reset the TC to factory and set it up again. You want it in router or static IP modem not bridge. (Reset will not delete the existing backup).

Actually let me do this for you.. although my main network is using 192.168.2.x instead of 192.168.1.x but the principle is the same.

First important thing.

1. You need to know to swap control of the airport utility from wireless to ethernet.. here.

2. When I swap to ethernet all my other airports disappear.. and only the TC plugged in by ethernet is available.

3. Normally I recommend a router setup but static also works.

Click on the TC to bring up the summary.. click on the edit.. (hidden by the floating help details about the error.)

4. Go to the Internet tab. I am using the standard IP of the TC. Fill it out exactly as follows except your DNS will be 192.168.1.254 (from your previous wireless info.. ) or just put in 8.8.8.8 .. doesn't matter as it is not used.

5. Go to the Network tab and fill out a suitable IP range. Use DHCP.. no NAT. Then click update.

6. Click on the wireless tab and select off for wireless.. you really don't want or need it running.

7. Fix the error/s

Click on ethernet unplugged.. this is your wan port on the TC.. Just ignore it and then you get a green light.

Now it is important to note if you have other airports they will not show up as long as you have airport utility selected to ethernet.

8. Fix it in the computer. You might need to reset the order to make sure wifi is the top of the list.. ethernet cannot be the top as it has no internet connection. Both should be green and showing connected.

Now check in Finder and you should be able to access the TC.. and check your browser to make sure you have internet connection.

So this is running fine for me.. I do note I had issues with speed on earlier Mac OS.. mixing wireless and ethernet like this.. so do post if it gives you issues.

Please note .. in the end a USB drive.. nice small self powered drive is faster, simpler, cheaper and more reliable with Time Machine than doing all this.

I turned WIFI OFF and connected TC to ethernet of MAC Pro. The TC hdd (as DATA disk) showed up in FINDER. Then using TIMEMachine backup was possible. The amber light keeps blinking. I verified the backup and it looks OK!

This seems to indicate that TC (2TB) behaves as a hdd. The WIFI can be connected after turning OFF the TC.

If you create a new network, you will have to switch networks in order to either access the Internet or perform Time Machine backups. Not an ideal situations.

The Time Capsule (TC) must be on the same network in order to do both.

One option would be to connect the Time Capsule to the router/gateway that is providing Internet access, but disable the wireless radios on the TC. Unfortunately, Apple does not recommend wired-only connections to the TC for Time Machine backups. FWIW, I have never experienced any issues doing so myself, but at least you have been "warned."

Backups to the Time Capsule occur only over your "local" network......not the Internet.....so there is really no downside to having an Internet connection available to the Time Capsule.

If you might be concerned about Internet data usage on your Internet plan, your backups will not affect your data plan, since the backups occur over the local network.

Another advantage to leaving the Time Capsule connected to the Internet.....you will be advised of any available firmware updates automatically.

As Tesserax mentions, Apple does not officially support backups using a wired connection when the Time Capsule wireless is disabled, but you could always try things out and see if they might work OK.

I backup to the Time Capsule using a permanent wired connection most of the time, and have not ever had any issues with this type of setup.

I can only see the TC. When I click on it, I then have the choices to create a new network,

Choose this one.

There is no difference.. although I am using El Capo not Sierra.. the setup is identical. Your problem is you have not configured the TC at all.. Apple depends on the wireless to do initial backup.. once that is done you can then swap to ethernet.