Credits to http://aclo
What is VPC Peering?
- Connection between two VPCs (single or with other AWS Account) within a single region.
- This is done via private IP address.
- Technology used is existing infrastructure of VPC, it is neither a gateway or a VPN connection.
Example VPC Peering:
Transitive Peering NOT Supported – VPC A cannot access VPC C via VPC B
If VPC B is change to this cidr block as above, it breaks the connection as there is overlapping internal address range (CIDR block).
- no overlapping CIDR blocks
- no peering connections
- cannot be on different regions