Turns out there was no need to mod uboot per se.
Issue was having eth0 minimally configured in /etc/network/interfaces file per the article https://jbevren.wordpress.com/2017/03/12/bringing-the-espressobin-up/ :
auto eth0
iface eth0 inet manual
auto lo
iface lo inet loopback
auto wan
iface wan inet dhcp
pre-up ifconfig wan up
auto lan1
iface lan1 inet dhcp
pre-up ifconfig lan1 up
