How to establish SSH connection with 60SOM and IG60 on builds without Network Manager entries for Ethernet?

Answer

With newer builds there are no default connections for Ethernet eth0 and eth1 anymore.
That prevents the device from getting an IP address to SSH in at.

In order to be able to establish an SSH connection again, it is possible to log in to the device through the serial debug console and define an Ethernet connection with this simple command:

# nmcli con add type ethernet con-name eth-connection ifname eth1
# nmcli con show
NAME            UUID                                  TYPE      DEVICE
eth-connection  a6183425-8fd1-4e06-9ff5-7a8d0bb5b346  ethernet  eth1

Routers providing IP addresses through DHCP will now issue an IP address to the 60SOM or IG60 again. If no DHCP is available, IP addresses can be added manually:

# nmcli con mod "eth-connection" ipv4.addresses "aaa.bbb.ccc.ddd"