thanks for the reply. I would like to remove the cisco 1721 and use only the 1841 for the two connections, but I want them indipendent. No failover.

Both methods would work, familiarize your self with concepts and commands from documentation then choose what suits you better.

Just to add to Paolo's post.

VRF will mean that you have 2 logical routers within the same router. You have separate routing tables and you can assign your interfaces to their particular vrf. This is complete logical separation.

PBR (Policy Based Routing) allows you to override the routing table to direct the router to the send certain packets one way and other packets another way regardless of what the IGP routing table says. Key thing to note is that there is only one routing table unlike VRF.

PBR is probably easier to setup but if you need complete isolation VRF is the way to go.

Jon