Private Space Peering enables you to establish a private network connection between dynos running in a Heroku Private Space and an AWS VPC you control. This connection does not traverse the public Internet. Prerequisites for peering The VPC must use a compatible IPv4 CIDR Block in its network configuration. The VPC must use an RFC1918 CIDR block (10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16). The