What's hogging upload bandwidth on my TimeCapsule router?

2600:8802:5200:152:1814:6ab1:99f:a8fe

Happy Thanksgiving to you as well!

You have a built-in app, called Network Utility, that can help narrow down who "owns" that IPv6 IP address.

To access it:

• Hold down the option key, and then, click on the Apple logo in the upper left-hand side of the macOS menu bar.
• Select System Information...
• From the System Information menu bar, select Window > Network Utility
• In Network Utility, select the Whois tab.
• Enter that IPv6 IP address, and then, click on Whois.
• The results will be shown in the window at the bottom of the app.

I just did and got the following results:

... and lo and behold, that address is in the range that Cox Communications "owns." Chances are you are seeing these addresses as any outbound IPv6 traffic is going to the Cox-provided DNS servers. What you can't tell from this app is where that traffic is going to from there. That would require more sophisticated methods to analyze the data traffic, like Wireshark.

To help determine which of your Macs is using the most bandwidth, you can use a third-party app, like PeakHour. From there you can try to figure out which app(s) are using the Internet to communicate. This could be done with enabling either the Mac's or a third-party application-level software firewall, like Vallum or Little Snitch, and then, monitoring which apps are the culprits.

Armed with all that information, you should be able to make an informed decision on how to tackle the "overage" issues using Cox services.

Thanks for providing us with an update.

What seems to have helped the most is Little Snitch.

Little Snitch and Vallum pretty much perform the same roles; however, I have to agree that the former is a bit easier to learn and use.

Anyway, I've been doing a lot of research in the meantime and just saw that Cox charged us $10 for another 50GB even after I spent the better part of an hour in a chat with an agent saying we didn't want to pay overages of any kind.

I was a Cox customer for years and was always happy with their service and only left them when I moved to an area that they didn't offer any services. Sounds like a good thing as it appears that they started capping their service since then. Sorry, that you're going through that ordeal, but it looks like that's becoming common especially with higher bandwidth offerings. (Don't have that issue with the 10 Mbps down here in
"fly-over" country. 😉)

But the irony, of course, is that whatever kernel_task was doing it has now stopped for the past 3 days or so.

FWIW. kernel_task is a core process of macOS. It's used in a lot of situations and would not necessarily be an issue. If your curious to want to know a bit more about it, the following article should prove helpful:

What Is kernel_task, and Why Is It Running on My Mac? - How-To Geek

I nearly turned off iCloud everything just to see if that was the culprit (I still suspect it might be), but again, by the time I could focus on the bandwidth hog, the bandwidth burn had disappeared.

Using any form of Cloud services, not just those from Apple, can be a resource hog ... as well as, potentially creating a lot of network traffic to/from the Internet. What I would suggest is to review each of the iCloud services that you are using and determine which are really required vs. like to have, and stop using the latter for the time being.

Areas to consider would be:

• iCloud Drive
  • Desktop & Documents Folders
  • Books
• Photos
• Apple icon > About this Mac > Storage tab > Manage... > Store in iCloud... & Optimize...

In the meantime, is your avatar referencing, Tesseract, or something else? Just curious.

Yes, actually it does. It's what happens when you try to come up with a username having a background in Aerospace engineering.

Peakhour is excellent utility that Tesserax has listed.. what is horribly sad is Apple removed SNMP for reasons known only unto the top level of Apple.. so any of the latest apple extreme or Time Capsules are totally useless.

Since Apple routers are totally inadequate & useless when it comes to tracking usage.. A most important function in the modern world of limited usage you simply need a better router.

An Asus router which monitors all devices on your network can quickly reveal what is using the bandwidth.

Even better is a cheap router like WRT1200AC running a special firmware called gargoyle.. it will show clear graphs and charts of exactly what computers or devices in your network are doing the damage.. you can keep using your apple router.. (until they break down.. and there is now no more.. ) as WAP. In the future you might want to consider Ubiquiti as a company that is advancing quickly excellent quality and reasonably cheap routers into the domestic arena. Already popular for SMB.

I haven't looked into this, but what happens to wireless TimeMachine backups without Apple hardware? I know a Drobo can be made a target, but my experience with those had me turn away from using them for that.

Before LaPastenague has a chance to respond, I would like to offer my "2 cents" on this.

FWIW, I stopped using my TCs for Time Machine about a year ago. Instead, I use a combination of a WD My Book Pro attached to my Mac mini and a Synology NAS for both the mini and my other Apple devices for Time Machine. The NAS also supports incremental backups for my Windows boxes as well ... and has many more features, like an iTunes Server to boot. Something you may want to consider going forward as the TC supply runs out.

Also, in my case, as my Apple base stations "wear out," I'm replacing my entire wireless network with Ubiquiti hardware. In my case I am using their UniFi line as my home has been pre-wired with an Ethernet backbone.