How to do: Internet link and pppoe servers from different RBs?

Hi Everyone,

I already have a pppoe server funcional, but now, I want to increase a remote lan for my pppoe server, and I want to use a second RB to provide internet link(nat-masquerade), and comunicate with mi firt RB by VPN to consult pppoe secrets and profiles, is it possible? Can you guys give-me an example of configuration.