JNCIS-SP: Juniper Networks Certified Specialist – Service Provider Routing (2022) — Question 61

Which two statements are true about IP and GRE tunnels? (Choose two.)

Answer options

• A. The protocol field is changed in the inner IP packet header
• B. Tunnel traffic is encrypted
• C. The TTL field is changed in the inner IP packet header
• D. Tunnel endpoints need a valid route to the remote endpoint

Correct answer: C, D

Explanation

Option C is correct because GRE tunnels encapsulate the original IP packet, and the TTL (Time to Live) field can be adjusted. Option D is also correct as both tunnel endpoints must have a valid route to communicate effectively. Options A and B are incorrect; the protocol field in the inner IP packet remains unchanged, and GRE tunnels do not encrypt traffic.