Refer to the exhibit. A network administrator has configured a GRE tunnel between R1 and R2 as shown. After completing the tunnel configurations, the administrator notices that the tunnel interfaces on both routers are down. All other interfaces are up and the pings through the ISP to the serial interface of each router are successful. What is the cause of the problem?

Refer to the exhibit. A network administrator has configured a GRE tunnel between R1 and R2 as shown. After completing the tunnel configurations, the administrator notices that the tunnel interfaces on both routers are down. All other interfaces are up and the pings through the ISP to the serial interface of each router are successful. What is the cause of the problem?

• Tunnel source configurations are incorrect.
• Tunnel destination configurations are incorrect.
• The MTU size has not been increased to 1492.
• GRE IP encapsulation has not been configured.

Exam with this question: CCNP ROUTE (Version 6.0) Chapter 7 Exam