Refer to the exhibit. A ping between the serial interfaces of R1 and R2 is successful, but a ping between their FastEthernet interfaces fails. What is the reason for this problem?

Refer to the exhibit. A ping between the serial interfaces of R1 and R2 is successful, but a ping between their FastEthernet interfaces fails. What is the reason for this problem?

• The FastEthernet interface of R1 is disabled.
• One of the default routes is configured incorrectly.
• A routing protocol is not configured on both routers.
• The default gateway has not been configured on both routers.

Exam with this question: CCNA Exploration 2: ERouting Final Exam