Router R1, a branch router, connects to the Internet using DSL. Some traffic flows through a GRE and IPsec tunnel, over the DSL connection, destined for an Enterprise network. Which of the following answers best describes the router's logic that tells the router, for a given packet, to apply GRE encapsulation to the packet?
正解:B
Explanation/Reference: Explanation: As for the correct answer: the process of routing a packet out a GRE tunnel interface triggers the GRE encapsulation action. As for the incorrect answers: There is no tunnel gre acl command. There is no IPsec tunnel interface. Finally, one answer refers to logic that would describe a router's logic when determining whether to encapsulate a packet into an IPsec tunnel.