I have a RHEL system which by default was running Python2.7 and Python3.4 
I needed Python3.6 for a project I wanted to work on and so I downloaded it and built it from source. I ran make and make install which hindsight may have been the wrong decision. 
Now I do not seem to have any internet connectivity. Does anyone know what I may have over written to cause this or at least where specifically I can look to track this issue down? 
Note: I can Putty into the Linux machine but it doesn't seem to have any other connectivity, specifically HTTPS
So after a lot of time slamming my head against the wall I got it worked out. My best guess is that the system (RHEL 7) relied on something from its default Python2.7 installation to handle SSL negotiations. Installing 3.6 alongside must have overwritten some pointer. Had I done this correctly, with altinstall all would have likely been fine.
The most frustrating part of this is that there were no error messages, connections just timed out. 
To fix this, I had to uninstall all Python versions and then reinstalled Python2.7 - Once Python2 was back in the system it all seemed to work well.
RHEL 7.6 - Built Python3.6 from Source Broke Network