Share Variables Between Two Arduinos Over LAN

We have an existing working code on a single Arduino Mega. It is reading in potentiometer variables and digital button presses and then actioning those on the digital and analog pins. We just need the code split on to two Arduinos (we have done this) and then need the inputs on one Arduino to be the outputs on the other Arduino. This is over a local LAN and we are using the ENC28J60 ethernet modules so the code would need to be based on the Ethercard libraries. We just also need a few note lines in the code on how to add in more variables as we wish. As a secondary goal we would like two way communications, but we are happy with one way if needs be.