Comprehensive and Detailed 250 to 350 words of Explanation From VMware Cloud Foundation (VCF) documents:

When deployingvSphere Kubernetes Service (VKS)—often referred to as Tanzu with VCF—within aVirtual Private Cloud (VPC)consumption model, the networking requirements are more stringent than a standard VM-only environment. This is because VKS relies on stateful services such asLoad Balancing(via the NSX Advanced Load Balancer or the native NSX LB) andNATto provide ingress and egress for Kubernetes pods and services.

In NSX architecture, any gateway that providesstateful servicesmust be configured inActive/Standbymode. While an Active/Active Tier-0 gateway is excellent for high-throughput ECMP routing, it cannot support stateful features because return traffic might arrive at the "Standby" (or alternative Active) node which does not share the same session state table, resulting in dropped connections.

Specifically, for VKS clusters integrated with the VPC model in VCF 5.x and 9.0, the Tier-0 gateway acts as the provider-side gateway. To ensure that the KubernetesLoadBalancerservice types andSNAT/DNATfor pods function correctly and maintain session persistence, the gateway must be anchored to a specific Service Router (SR) on an Edge node. This is only possible in anActive/Standbyconfiguration.

Option B (Non-Preemptive) is a failoversettingbut not the primary architectural requirement. Option D (IPv6) may be used depending on the specific network design, but it is not a mandatory requirement for VKS functionality. Option A is incorrect as route maps usually require "Permit" rules to actually function. Thus, the verified architectural prerequisite for a VKS/VPC-enabled workload domain is anActive/Standby Tier-0 Gateway.

===========