Connectivity

This section covers how separate networks are joined: one VPC to another, an on-premises network to AWS, and a VPC to a service without crossing the public internet. The right choice depends mostly on scale, and a design that works for three VPCs rarely survives thirty.

For VPC to VPC, start with connecting VPCs. It compares VPC peering with a transit gateway. Once the number of VPCs grows, Transit Gateway is the hub that replaces a mesh of peering connections. The implementation guides show how to share it across accounts.

For an on-premises network, connecting an on-premises network to a VPC compares VPN, Direct Connect and their combinations. Direct Connect has its own subsection.

For private access to AWS services, SaaS providers or other accounts, start with AWS PrivateLink and the VPC endpoints page. AWS App Mesh, which once appeared in service-to-service designs, reaches end of support on 30 September 2026; its page records what replaces it.