can't understand how to configure GRE tunnel through ASA
i have one router with public ip, connected to internet
ASA 8.4 with public ip connected to internet
router with private ip behind ASA.
have only one public ip on ASA with /30 mask
have no crypto
have network behind ASA and PAT for internet users.
can't nat GRE? cause only TCP/UDP nated(?)
with packet-tracer i see flow already created but tunnel doesn't work