Two cities merging IT operations both use overlapping 10.0.0.0/8 ad…

Question

Two cities merging IT operations both use overlapping 10.0.0.0/8 addressing and must connect selected workloads into AWS without renumbering every on-premises network on day one. Which approach best addresses the overlapping CIDR constraint?

Accepted Answer

Avoid IP-routed connections that require unique CIDRs for the overlapping ranges; use patterns such as AWS PrivateLink, application proxies, or a phased renumbering plan for networks that must route directly. — Two towns with the same street numbers cannot share one GPS map without chaos. Overlapping CIDRs break simple routed attachments, so you either hide behind PrivateLink or proxies or you plan a renumbering wave. Peering and Transit Gateway still need unique, routable addresses.

Answer

Create VPC peering between AWS and both cities' networks even though the CIDRs overlap, because peering ignores address conflicts.

Answer

Attach both overlapping on-premises ranges to the same Transit Gateway route table and rely on longest-prefix match alone.

Answer

Assign identical CIDR blocks to two VPCs in the same Region and peer them to prove overlap is supported.

Two cities merging IT operations both use overlapping 10.0.0.0/8 addressing and must connect selected workloads into AWS without renumbering every on-premises network on day one. Which approach best addresses the overlapping CIDR constraint?

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