Exam Professional Cloud Network Engineer topic 1 question 148 discussion

D is the correct answer. The question has 3 criteria. High availability, IPv4 and IPv6 support, and translate the front end port to a different backend port. Answer A - Can not be correct because a Network load balancer is pass-through, the front end port and backend port will allways be the same. Answer B - same reason Answer C - Does not meet the HA requirement Answer D - Meets all 3 requirements, HA with 2 instance instance group, IPV4 and 6 support, and the port change requirement provided by the proxy component of the TCP LB. https://cloud.google.com/load-balancing/docs/tcp

A is the correct, since with need to support IPV6: "Target pool-based network load balancers support only IPv4 traffic, and only support the TCP and UDP protocols." https://cloud.google.com/load-balancing/docs/network/networklb-target-pools

Must be D because of the port forwarding

D because of the port mapping

To ensure high availability for an application that is exposed externally using both IPv4 and IPv6 via TCP on port 700, you should use a TCP proxy with a backend service that contains an instance group with two instances. A network load balancer can only be used to expose applications that are exposed using HTTP or HTTPs. A target pool backend can only be used with a network load balancer. A zonal network endpoint group can only be used with a TCP proxy. Therefore, the best option is to create a TCP proxy that uses backend services containing an instance group with two instances. Here is an example of how to create a TCP proxy that uses backend services containing an instance group with two instances:

Answer is D: The questions mention High Availability. Although an External Network (passthrough LB) can do IPv4 and IPv6 and port forwarding - it's regional... External TCP Proxy is global...

Tricky question. D & C do not mention LB, just TCP Proxy. To me it's A

This question is all over the place. Firstly options C & D all point to internal TCP Proxy LB which doesn't support IPv6. Same with Option B (Target Pool) which doesn't support IPv6. Now answer A supports IPv6, but passthroughs maintain the same port throughout whereas in this case the requirement is that 700 should change to 800. The right answer would be External TCP Proxy Load-Balancer.

A is correct tcp proxy in eventually part but part of NLB https://cloud.google.com/load-balancing/docs/tcp

you need to have proxy supported Load balancer in between to do port forwarding service. I checked on GCP console and could find option of mentioning ports for frontend and backend only in TCP proxy LB. on top of that it also supports IPv6. Hence Option D

TCP proxy supports IPV6: https://cloud.google.com/load-balancing/docs/tcp#benefits

In my opinion D is correct. The network loadbalancer just supports pass-through. But in this case, we need to forward it to another port. That is not pass-through. https://cloud.google.com/load-balancing/docs/load-balancing-overview?hl=en#summary-of-google-cloud-load-balancers

Totally assumed LB after the TCP Proxy. Tricky stuff. Answer should be A.

Why not D. TCP Proxy is Global and supports IPv6 with a single port between 1-65535. https://cloud.google.com/load-balancing/docs/forwarding-rule-concepts#port_specifications

Exposed port 800 elimated C and D, that isn't support this port. A is wrong too, https://cloud.google.com/load-balancing/docs/backend-service#backends. B is correct.