You will need to configure a gateway for both the Ethernet ports.  The user manual indicates that only one port can be configured with a default gateway (using the front panel or netconfig).  However, with advanced routing you can configure a gateway for both ports (eth0 and eth1).  You must add commands to set up static routes in the /etc/rc.d/rc.M startup script. There is an easily spotted comment in the rc.M file showing where to add the commands. For more information, read this Product Note or contact EndRun Technical Support.