I've figured out how to connect a SSH shell using the Ethernet port on the i.MX8 eval board.
In the COM port shell
$ ifconfig eth0 up
$ ifconfig
Look for the IP address after inet addr
e.g.
eth0 Link encap:Ethernet HWaddr 00:04:9f:07:15:9a
inet addr:169.254.42.78 Bcast:169.254.255.255 Mask:255.255.0.0
Then I start another terminal e.g. I'm using Tera Term to the IP address above 169.254.42.78
The username is root