Thanks for the answer,
I configured the tunnel in the same VRF using the tunnel vrf vrfname command. The GRE Tunnel is UP, I even went up a /30 network on the tunnel interface and I have communication on that network.
The PE I use is a Catalyst 3650 Switch, I can perform exactly the same configuration on a Cisco router instead of a Switch and replace the PE with this router and it works perfectly, without any problem.
I did a SPAN on the PE and analyzed with Wireshark the traffic received on the CE-PE interface and I see that the ICMP request made on the CE to CE is seen on the interface, but shows "no response found!". When I analize the interface between PE-P (where the request should be forwarded) we don't see the ICMP Request forwarded.
When replacing the catalyst 3650 switch with the 2901 router and doing the same SPAN, we see the ICMP request being received on the CE-PE interface and forwarded on the PE-P interface. My question is: Is there any limitation that justifies the same configuration working on the router, but not on the switch?
I'll try to draw the topology to make it easier to understand.
