Time capsule won’t backup via WiFi or Ethernet

A "Quick Erase" from AirPort Utility will wipe the Time Capsule hard drive in a few minutes. You can start a new backup as soon as you want after the drive has been erased. Run Time Machine on one Mac and let the backup complete before you back up the next Mac.

Yeah.. there are times it just gets like.. why I am carry rocks up a hill.. to throw them down again.. so it feels lighter when going down..

A. The DNS server is 192.168.1.254 but it is greyed out.. so it might be worth filling it in.

It is totally irrelevant so whether it has DNS or not is of no concern to your network.

B.. I will do this another way..

C. IPv6 is on your local computer.. under network preferences.. and I gave you the screenshot. But I did forget to say reproduce this. The box where it says configure IPv6:

On your computer it will default to Automatically. This is wrong setting 50% of the time.. you need to alter it to link-local only.

Now come back to B.. The problems with main router giving you the wrong domain.. but in a situation where you cannot manually fix it.. I am going to suggest something else on top of the suggestions already made..

I still want you to go ahead..

A. Set a static IP on the Internet tab.. but give it the following EXACTLY.. you will need to fill it in yourself.

The only thing you don't fill in is domain which is showing grey in the bottom there.. just leave that entry blank.

Click on Internet Options and set to IPv6 link local only.. then click save.

Now the new bit is we are going to configure the TC as a dhcp server.

Again exactly as my picture.. I have messed up my own TC to do this for you.

Click on Network Options..

And change the lease time to one hour.

Again click save..

When you are back at the network tab click update..

And continue..

At this point let me suggest you do a full restart of the network.. power everything down in any order..

Power up exactly like this..

1. ATT modem wait 2min.
2. Time Capsule (wan port must be plugged to ATT modem LAN port.. 1 or 2 or 3 or 4) .. wait 2min.
3. Computers that you connect to the TC .. wait until they are connected to the internet.
4. Everything else.. whatever whichever wherever.

There is nothing else you need to configure on the computer.. which means it will stay in fully automatic mode.. and you can carry it around.. and it will pickup IP with all the details correctly wherever you go.

But do open the Network Preferences and check that you have the correct DNS (It should be 192.168.1.254 and 8.8.8.8) and either no Domain or Local.

Let me explain what this new setup does..

The TC is now an active true (not NAT) router on the network.. it is going to hand out addresses directly to whatever clients join it .. from its small pool of IP which are stolen (borrowed) from the main router.. That makes sure your computer is in a full bonjour environment and will have much less problems with the TC.. although the proof of that is coming.

Now try a backup and tell me what happens.

Can you post me some screenshots.. that will help.

I understand you are running two different wireless networks.. one from the ATT.. and one from TC but I am abit lost as to how you have network configured the TC to do this.. Is it in double NAT?

These shots help.

If it is double NAT then it would be best to get it back to a more standard setup

Certainly if you used the wizard it should have put the TC in bridge (that is router bridge) and you can then have issues with the IP address of the TC.. you can also have domain issues.. so a screenshot from your computer of the actual IP you get when connected as well as the domain and DNS.

So these ones.

My current setup here will definitely lead to issues.. I am testing another router in between.. so it has changed both DNS and Domain to values that are not valid on the TC.

Is it possible that this could be from some corrupt file on my laptop that is causing the bottleneck?

Yes.. although you previously said that you had at least one completed backup after you wiped the old backup. I know it did not work first time around but it did work.

Open the console in your Mac and type backup into the search.

That should then give you all the log messages from TM and show where and what has failed..

You can check your local disk but to do so you need to need to boot to the recovery.. and then use disk utility to run the check. It could just be a failing disk.

You can also delete time machine current configuration which is sometimes worth it.. but I suspect something else is going on.

My recommendation now is to download Carbon Copy Cloner and give it a run.

My own personal setup is now to use Time Machine only as a test (so I can effectively answer your questions) because it fails so frequently.. but my real backup is handled by CCC.. it is free to use for a month. Do at least one backup on your TC using CCC and that will give you a lead of where issues exist.. Local computer, TM, TC or network..

Honestly Time Machine has now reached a point where it is too unreliable to be trusted.

Sorry that we have not so far been much help even with our complicated setups.

BTW did you turn off power nap in the computer.. I think I mentioned earlier that you must not have backups attempting to run while the Mac is sleeping.

It also sounds like it is backing up very slowly.. it should backup at 40-60GBytes/hour even over wireless.. if it is much slower than that.. something else is happening.. maybe network problem in the computer??

On your Mac.....

Hold down the option key while you click on the Time Machine "clock" icon at the top of the screen

Click on Verify Backups

Let the process run until it completes, or until you see an error message

If an error message appears, post back with the exact text of the message

Unfortunately, this indicates that your backup file is corrupted and not usable. The solution is to delete the backup file and start over again with a new backup.

The simplest way to do this is erase the Time Capsule hard drive, but the downside to doing this is that you will lose any other backups that other Macs may have made to the Time Capsule.

Quite a bit more complicated....but doable....is to erase only the backup file for your Mac, which will not affect any of the other backups or data on the Time Capsule.

If you could tell us which way that you want to go, we'll post back with step by step instructions.

If you have a MacBook Air, it has no Ethernet port on the device, so you must be using an adapter of some sort that will convert Thunderbolt to Ethernet or USB to Ethernet.

Unfortunately, the adapters do not alway work as well as advertised, so that might be a possibility for your issue in trying to use Ethernet to back up.

If WiFi works for the backup, then you know that you likely have an issue with either your adapter or Ethernet cable.....possibly both.

Reading back through the thread there is some info missing.

What model is your TC? Is it the tower model.. AC wireless then it is gen5. Or is it previous version flat one.. and thence old. Even a gen5 bought at release in 2013 is now 5 years old.. and well due replacement.

What OS are you running on the MBAs? Are both the same?

Is the TC running as your main router or bridged? This is particularly important as bridge mode has caused loads of problems on later OS.

Have you turned off power nap in the power settings. Apple .. releases its pearls to the swine with great reluctance.. but they did finally fess up that power nap will cause disasters with time machine.

I have noticed is that when I go back to check on the backup progress and see it has failed, there is consistently a message about the laptop itself being almost out of space. There’s about 16GB left. Could this be the cause of the problem?

I don't think so.. it could be causing slow downs.. especially if your MBA has restricted RAM. Open activity monitor and check how much swap is being used.

You do need to get some files off the laptop though. And storing them on Time Capsule (TC) is not safe.. nor is using Time Machine (TM).. you need to off load those files to a USB drive plugged into your computer. And you can then backup that drive to TC via TM.