Ping Issues using Thunderbolt to CAT

So a little while ago I was having wireless problems and wrote a little monitoring tool that was really just a wrapper around ping. I still find it useful for displaying current connectivity at a glance.

But I also added the ability for it to write a log of its connectivity, and then wrote a perl script to parse the log and display a summary graph. It sounds like just what you're looking for:

The only hitch is that I developed it on Linux, but from what I can tell, ping should work the same on a Mac. If you're interested, here is what to do:

If you have git:

$ git clone 'https://github.com/NickSto/uptest.git'

If you don't:

$ mkdir uptest && cd uptest
$ wget 'https://raw.github.com/NickSto/uptest/master/uptest.sh'
$ wget 'https://raw.github.com/NickSto/uptest/master/upanalyze.pl'

Then run the monitoring tool for a few hours, logging to a file (run ./uptest.sh -h to read its usage):

$ ./uptest.sh 15 -l uptest_log.txt

Then you can print the histogram with upanalyze.pl:

$ ./upanalyze.pl uptest_log.txt

Stars are bad (dropped pings): a full line of stars means you didn't have any connectivity that whole hour.

In my case the problem was IPv6. Websites like Facebook, Google.com and Youtube use IPv6 and work fine while other's don't support it yet.

I couldn't figure out the issue exactly (and the right configuration for IPv6) but I disabled IPv6 and the issue was resolved. This is all I care at this point.

The commands for El Capitan:

Turning off IPv6 support for ethernet:

networksetup -setv6off Ethernet

Disabling IPv6 for wireless:

networksetup -setv6off Wi-Fi

If you ever need to re-enable:

networksetup -setv6automatic Wi-Fi
networksetup -setv6automatic Ethernet

I will edit this if I ever find the correct setting for IPv6 instead of a full disable.