So, I posted this issue on the Apple support community site, and got helpful answers in just a day. I was able to set up a wired connection, took about 12-14 hours, but the download finished. Nothing to do with Century Link.
Where are you getting the error? Is it on the Apple device?
It's happening in the Mac Store application in macOS. I had something similar trying to update an iPad to 14.2 where it stuttered and stalled on just 714MB - took several hours. When it fininshed and started the 'prepare' phase, it said the download failed, then told me the update will now be 3.56GB instead of the original 714MB. #Fun
Pretty sure this is a combination of SSL errors, routing problems, as well as the usual gapping problems at the provider (CenturyLink) causing timeouts.
There have also been problems with the routes to Microsoft update servers. I finally was able to successfully update my Win10 VM to Oct 2020 today. There were real problems with sub-100kB links to update.microsoft.com. Again, pretty sure this is mostly caused by CL.
MarkJFine , this is why I asked where the OP is getting the error messages -- the network is actually working, but the pathways are clogged or slow, and Apple (and now Windows) interprets this as there being no network connection, when in fact there is one.
CL is doing a number on updates, it seems. I have to go elsewhere for my Apple and Windows updates, as they no longer work reliably from home.
