I am implementing a WAN link that span a carriers extranet environment. The link will have an inside interface (our router) and an outside interface (their router). When we send traffic to our remote site the traffic will be subject to NAT allowing routing across the SP extranet. In order to secure the data we need to implement an IPSEC tunnel. The tunnel type needs to be GRE and because NAT is being done we need to used ESP. Could anyone suggest a template that I could use for the two routers that we control, in order to set all of this up?
Any help well rated.