Exam Professional Cloud Network Engineer topic 1 question 64 discussion

I will go with A Reason: If the VPN logs show a no-proposal-chosen error, this error indicates that Cloud VPN and your peer VPN gateway were unable to agree on a set of ciphers. For IKEv1, the set of ciphers must match exactly. For IKEv2, there must be at least one common cipher proposed by each gateway. Make sure that you use supported ciphers to configure your peer VPN gateway. https://cloud.google.com/network-connectivity/docs/vpn/support/troubleshooting#:~:text=If%20the%20VPN%20logs%20show,of%20ciphers%20must%20match%20exactly.&text=Make%20sure%20that%20you%20use,configure%20your%20peer%20VPN%20gateway.

While it's necessary for BGP sessions to be established with both onprem routers to activate ECMP (option D) this is a symptom rather than the cause. The message in the logs indicates a problem with negotiating a connection, which supports the hypothesis that one of the VPN tunnels is incorrectly configured (option A).

One BGP session not established: This directly confirms that one of your routers isn't correctly peering with the Cloud Router, preventing traffic distribution.

The correct answer is D. BGP sessions are not established between both on-premises routers and the Cloud Router. When you have multiple VPN tunnels between your on-premises network and GCP, BGP is used to advertise routes between the two networks. If BGP sessions are not established between both on-premises routers and the Cloud Router, then the on-premises routers will not be able to learn about the routes that are advertised by the Cloud Router. This will cause all of the traffic to flow across the single VPN connection that is working.

I think it’s A

BGP sessions are not established between both on-premises routers and the Cloud Router. - this observation is already made in question . Hence this cannot be answer. correct answer is A

https://cloud.google.com/network-connectivity/docs/vpn/support/troubleshooting#:~:text=If%20the%20VPN%20logs%20show,of%20ciphers%20must%20match%20exactly.&text=Make%20sure%20that%20you%20use,configure%20your%20peer%20VPN%20gateway

Option D is the correct answer because it correctly identifies the root cause of the problem. The fact that BGP sessions are not established between both on-premises routers and the Cloud Router means that the routers are not sharing routing information with each other or with the cloud network. This can cause traffic to be routed across a single VPN instead of being load balanced across multiple connections. Option A is incorrect because it only addresses one of the VPN sessions, and the problem is not limited to just one of the sessions. Option B is incorrect because a firewall issue would likely cause a complete loss of connectivity, rather than just affecting load balancing. Option C is incorrect because the question doesn't mention the need for a load balancer, and load balancing is not the root cause of the problem.

• A. One of the VPN sessions is configured ***** incorrectly.

I will go with A. You can not use the same ASN, needs to be different

Answer is : A

right option is B, for the table in this link https://cloud.google.com/kubernetes-engine/docs/concepts/alias-ips#cluster_sizing_secondary_range_pods

Answer is A: https://cloud.google.com/network-connectivity/docs/vpn/concepts/classic-topologies This seems to be a case for classic VPN. The BGP session is not established because the VPN session is not configured correctly. LBs are not needed... Thoughts?

A is answer

I'll go A, only A makes sense in this situation.

Correct one C

I'm going with D here. Lack of load balancer isn't preventing one of the BGP sessions from establishing. The second BGP session not being established is preventing load balancing to the alternate vpn. As far as the wording of D, (BGP sessions are NOT established between BOTH on-premises routers and ...) think of it this way: Not both, only one. If only one of your eyes can see, then you cannot see with both eyes.