Installing missing Intel I217-V for Debian

This firmware was not included as part of a readily available package within Debian and so needed to be installed from Intel's website:

https://downloadcenter.intel.com/download/15817/Network-Adapter-Driver-for-PCI-E-Gigabit-Network-Connections-under-Linux-

Firstly ensure we have the appropriate kernel headers with:

sudo apt-get install linux-headers-$(uname -r)

So we simply unzip the gzip file:

tar zxvf e1000e-3.2.*

cd e1000e-3.2.4.2

make install 

and then activate the module with:

sudo modprobe e1000e

 Finally confirm the module is installed / in use with lsmod:

lsmod | grep e1000e