A VPC must serve IPv6 clients while keeping the existing IPv4 infrastructure running during a gradual migration. What's the right approach?
A.Dual-stack — add IPv6 CIDRs to the VPC/subnets alongside IPv4
IPv6 alongside IPv4 = the transition pattern. Correct.
B.IPv6-only subnets immediately
IPv6-only breaks the running IPv4 workloads.
C.NAT64 translation on a custom instance
NAT64 is a translation hack — native dual-stack is cleaner.
D.A separate IPv6-only VPC with peering
A second VPC duplicates infrastructure — no benefit over dual-stack.
Why this answer
Dual-stack associates IPv6 CIDR blocks with the existing VPC/subnets — resources get both IPv4+IPv6 addresses and either protocol works during transition. Egress-only IGW handles outbound-only IPv6 for private resources.
Correct answer: A · Last reviewed 2026-11-05
Official AWS references
Practice this interactively
Answer without seeing the solution first in the Hybrid Connectivity practice session.
Practice Hybrid Connectivity