300-420 Question 207
Single answerA company has implemented a Group Encrypted Transport VPN (GET VPN) to secure communication between multiple branch offices and the headquarters. During deployment, they notice inconsistent packet delivery and latency issues between some branch offices. Which of the following is the MOST likely cause of the issue?
- A
The Group Domain of Interpretation (GDOI) key server is overloaded with requests from branch routers.
- B
The routing protocol used in the network is not synchronized with the GET VPN rekeying process.
- C
The GET VPN policy has been incorrectly applied to the branch routers.
- D
The branch routers do not have multicast routing enabled, which is required for key distribution.
Show answer and explanation
Correct answer: D
Explanation
GET VPN relies on multicast for the distribution of encryption keys to group members from the GDOI key server. If multicast routing is not enabled in the network, the branch routers may fail to receive the necessary keys, causing encryption issues and inconsistent packet delivery. Ensuring multicast is properly configured is critical for the successful operation of GET VPN.
- A. Incorrect.
The GDOI key server can handle multiple requests as it is designed for scalability and performance. While an overloaded key server can cause issues, it is less likely to cause inconsistent packet delivery and latency between branch offices.
- B. Incorrect.
GET VPN operates independently of the routing protocols in the network. While routing protocol misconfigurations can cause network issues, they are not directly related to the rekeying process in GET VPN.
- C. Incorrect.
An incorrectly applied GET VPN policy could cause encryption or traffic forwarding issues, but it would not specifically result in inconsistent packet delivery and latency as described.
- D. Correct.
Multicast routing is essential for GET VPN because the GDOI key server distributes keys to group members using multicast. If multicast routing is not enabled, key distribution might fail, leading to issues like inconsistent packet delivery and latency.