Stretch setup ssh
To install ssh, install the package as normal with apt-get:
apt-get install openssh-server
Debian Stretch by default disallows logins directly from the user "root". Additionally, SSH will not allow remote connections without a password or valid SSH key pair. This means in order to SSH to the device, a user account must first be created, and a password set:
useradd --create-home --shell /bin/bash newuser passwd newuser
After this setup it is now possible to connect to the device as user "newuser" from a remote PC supporting SSH. On Linux/OS X this is the "ssh" command, or from Windows using a client such as PuTTY.