Corrrect Answer is (A): TCP Proxy Load Balancing is implemented on GFEs that are distributed globally. If you choose the Premium Tier of Network Service Tiers, a TCP proxy load balancer is global. In Premium Tier, you can deploy backends in multiple regions, and the load balancer automatically directs user traffic to the closest region that has capacity. If you choose the Standard Tier, a TCP proxy load balancer can only direct traffic among backends in a single region. https://cloud.google.com/load-balancing/docs/load-balancing-overview#tcp-proxy-load-balancing

A is the correct answer. D is not correct. CDN works with HTTP(s) traffic and requires caching, which is not a valid feature used for mail server

I go for (A) because Network Load Balancers are Layer 4 regional, passthrough load balancers: so it didnt work as global LB ("different GCP regions")

This is probably an old question 2-3 years ago, GCP introduces a "proxy network load balancer" So, in 2024, we have: - application load balancer, global, external-only, multi-region backends, only for HTTP and HTTPS, do not preserve clients' IP - "legacy" network load balancer (aka "passthrough"), external or internal, single-region, tcp or udp, preserve clients' IP - "new" network load balancer (aka "proxy"), global, external or internal, multi-region backends, tcp or udp, do not preserve clients' IP Here, we want: - global - external - multi-region - non-http => proxy network load balancer is the solution This maps to A (generic answer) or B (but only in proxy mode: passthrough won't work)

The company can achieve location-based routing of customers to the nearest mail server in Google Cloud Platform (GCP) using a Network Load Balancer (NLB)

The company can achieve location-based routing of customers to the nearest mail server in Google Cloud Platform (GCP) using a Network Load Balancer (NLB)

There is no direct SMTP support in TCP proxy load balancer, hens it cannot be A. Google Cloud best practices recommend Network Load Balancing (NLB) for Layer 4 protocols like SMTP.

B) Create a Network Load Balancer to listen on TCP port 995 with a forwarding rule to forward traffic based on location. Explanation: Port 995 implies this is SSL/TLS encrypted mail traffic (IMAP). Network Load Balancing allows creating forwarding rules to route traffic based on IP location. This can send users to the closest backend mail server. TCP Proxy LB does not allow location-based routing. HTTP(S) LB is for HTTP only, not generic TCP traffic. Cloud CDN works at the HTTP level so cannot route TCP mail traffic. So a Network Load Balancer with IP based forwarding rules provides the capability to direct mail users to the closest regional mail server based on their location, meeting the requirement.

"A" is the most suitable answer. Mail servers use SMTP which run on TCP. This excludes C, D which are HTTPs based. Option B is not global which excludes it as well. The following page elaborates on global external proxy load balancing under the premium tier which meets the needs for this question and aligns with option A https://cloud.google.com/load-balancing/docs/tcp#identify_the_mode

https://cloud.google.com/load-balancing/docs/tcp

B is the ans

The correct answer is B. To route customers to the nearest mail server based on location, the company can create a Network Load Balancer. The Network Load Balancer can listen on a specific TCP port (e.g., port 995 for mail traffic) and use a forwarding rule to forward traffic to the nearest mail server based on the client's location. This can be achieved by using a combination of the Load Balancing service and the Geo Map feature to route traffic based on the client's IP address. TCP Proxy Load Balancing (A) is not suitable for this scenario as it is designed for non-HTTP(S) traffic, and it does not use client location information for traffic routing. Cross-Region Load Balancing (C) is also not suitable as it is designed for HTTP(S) traffic and does not use client location information for traffic routing. Cloud CDN (D) is designed for caching content and delivering it from the nearest point of presence (POP) to the user, but it does not route traffic to different servers based on the client's location.

TCP Proxy Load Balancing is implemented on GFEs that are distributed globally. If you choose the Premium Tier of Network Service Tiers, a TCP proxy load balancer is global. In Premium Tier, you can deploy backends in multiple regions, and the load balancer automatically directs user traffic to the closest region that has capacity. If you choose the Standard Tier, a TCP proxy load balancer can only direct traffic among backends in a single region.

At a glance, A seems wrong because it's a proxy solution and the question ask to route the traffic. But, in Premium Tier its possible to have a global forwarding rule and the backends in any region so it's the only solution for this. the other options are HTTP or Regional so they are wrong

A is correct answer

Corrrect Answer is (A): TCP Proxy Load Balancing is implemented on GFEs that are distributed globally. If you choose the Premium Tier of Network Service Tiers, a TCP proxy load balancer is global. In Premium Tier, you can deploy backends in multiple regions, and the load balancer automatically directs user traffic to the closest region that has capacity. If you choose the Standard Tier, a TCP proxy load balancer can only direct traffic among backends in a single region. https://cloud.google.com/load-balancing/docs/load-balancing-overview#tcp-proxy-load-balancing

Ans should be A. TCP Proxy Load Balancing is intended for TCP traffic on specific well-known ports, such as port 25 for Simple Mail Transfer Protocol (SMTP).