How it works:
By changing the way you ssh to a machine, you can reuse your initial ssh connection to save time when connecting.
Edit your ~/.ssh/config file to have this:
ControlPath ~/.ssh/sockets/%[email protected]%h:%p
We avoid problems of reusing the default /tmp but storing our connections in their own directory.
Be sure to create the directory:
mkdir -m 700 -p ~/.ssh/sockets