VPC Peering

1. It is a network connection done between two VPC that enables to route traffic between them (IPv4 and IPv6).

2. You can have VPC peering between VPC’s in same account, different account, same region and even across region known as Inter region VPC peering (IPv6 is not supported).

3. AWS uses the existing infrastructure of a VPC to create a VPC peering connection, it is neither a gateway nor a VPN connection, and does not rely on a separate piece of physical hardware.

4. There is no single point of failure for communication or a bandwidth bottleneck.

5. It is simple and cost-effective way to share resources between regions or replicate data for geo redundancy across regions.

To establish a VPC –peering connection

·       The owner of VPC sends a request to the owner of peer VPC to create a VPC peering connections.

·       The peer VPC can be owned by you or another AWS account.

·       Peer VPC cannot have CIDR block that overlaps with requester VPC.

·       The owner of peer VPC accepts the VPC peering connection request to activate it.

Multiple VPC peering

·       A VPC peering connection is a one to one relationship between two VPCs.

·       You can create multiple VPC peering connection for each VPC that you own.

·       Transitive peering relationship are not supported.

·        VPC peering does not support edge to edge routing.