This ethernet connector may not work out of box, so there must install the right driver from Realtek site.
inxi -N ## tells the cadget and driver
Download the driver:
http://www.realtek.com.tw/Downloads/downloadsView.aspx?Langid=1&PFid=7&Level=5&Conn=4&DownTypeID=3
Install the driver:
Unpack the tarball :
tar vjxf r8101-1.aaa.bb.tar.bz2
Change to the directory:
cd r8101-1.aaa.bb
If you are running the target kernel, then you should be able to do :
sudo ./autorun.sh
You can check whether the driver is loaded by using following commands.
lsmod | grep r8101
ifconfig -a
After that r8101 kernel module is loaded and in nm the connection came up. But there is no mac address, so it has to make a random mac address like
sudo ifconfig eth0 hw ether 00:04:FE:11:22:38
Now the internet is working. For making it persistent, edit the /etc/network/interfaces file
sudo nano /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
pre-up ifconfig eth0 hw ether 00:04:FE:11:22:38
With Mint 18 the file goes like
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
pre-up ifconfig enp3s0 hw ether 00:04:FE:11:22:38
Save and quit
Ctrl o
Ctrl x