AT&T Uverse IPv6 vs. Mac OS X 10.(old)

[Jerry Weiss]

> 
> On Mar 26, 2016, at 11:31 AM, Tapley, Mark <mtapley at swri.edu> wrote:
> 
> (Apologies in advance to non-Apple users)
> 
> Mac folks,
> 	Last week AT&T “upgraded” our Uverse service. All of our Macs running anything 10.6.8 or older quit working. 
> 	Cure was to turn off IPv6: System Preferences -> Network -> Advanced -> TCP/IP -> iPv6 to “Off” instead of “Automatic”.
> 
> 	Symptoms were *very* widespread, and matched reasonably well to failing hard drive or failing memory - system freeze, spinning beach-ball forever, can’t read directory, etc. etc. etc.  On the G3, I rebooted in single-user mode and actually got part way through the output of “ps -aux” in one case before freezing. However it did respond to Ctl-C and would then do a “ps -a” no problem, just no “ps -aux”.  We were a bit silly, didn’t read our Uverse email, and didn’t test other systems before hooking more old systems into the network - which then didn’t work. We were panicing about viruses, pulling hair out, sacrificing goats ...
> 
> 	Systems affected were :
> 
> iMac G3 Mac OS X 10.4.11  - ethernet
> PowerBook G4 Mac OS X 10.4.11 - wi-fi
> iMac 2011 intel Mac OS X 10.6.8 - wi-fi
> 
> 	Apologies if this is a known bug, but it really puzzled us for a while because the effects were so systemic; I hope I can prevent anybody else from getting a nice new (needless) hard drive like the 2011 iMac did…
> 
> 					- Mark
> 					210-522-6025 office         210-379-4635    cell
> 

On old boxes where I keep Linux (Ubuntu 7.x) and older hardware for my vintage work, I logged in one day and experienced major remote network problems and freezes.  Granted this version of Ubuntu is running IPv6 code that is far from mature.

My initial detective work showed problems with the IPv6 DNS resolution.  I am also a Uverse customer. Disabling IPV6 was the cure.  I’ve done this on my Macs running  10.1x as well and the number of similar but less frequent problems now approaches zero.

Jerry