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?
A. When the packet received on the LAN interface is permitted by the ACL listed on the tunnel gre acl
command under the incoming interface
B. When routing the packet, matching a route whose outgoing interface is the GRE tunnel interface
C. When routing the packet, matching a route whose outgoing interface is the IPsec tunnel interface
D. When permitted by an ACL that was referenced in the associated crypto map
Correct Answer: B
As for the correct answer: the process of routing a packet out a GRE tunnel interface triggers the GRE
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.