VPC peering
Basic Concept
VPC peering is a kind of cross-VPC network interconnection service, enabling private IPs to route traffic between peer VPCs as if they belonged to the same VPC. You can interconnect private networks of the same or different users in the same region. At the same time, by configuring route policies at both ends, interoperate traffic across different private networks is realized. Peering is not dependent on a separate piece of hardware, so there is no single point of failure or bandwidth bottleneck, and more application scenarios are supported, such as cross-region co-server games.

Product Features
- High quality: The communication of resources between different private networks is not affected by the quality of the public network and there is no limit on bandwidth, availability is significantly increased while latency and packet loss are reduced.
- Security: The communication of resources between private networks in the same region is implemented through the internal network of JD Cloud without passing through the public network, avoiding the risk of data being eavesdropped during transmission.
- Saving of public network costs: The communication of resources between private networks is implemented via VPC peering by means of private IP addresses without the need to use public IP addresses, saving bandwidth costs.
No Transfer of Peering Interoperability
Peering allows private networks to interconnect two by two. However, such interoperability will not transfer. As shown in the diagram below, peering is established between VPC a and VPC b and also between VPC a and VPC c. However, as the peering will not transfer, private IP traffic between VPC b and VPC c is not interoperable and communication can be implemented via the public network.

Status Description
- Initialization: VPC on one side establishes VPC peering, while VPC at the opposite terminal does not establish VPC peering.
- Connected: VPCs on both sides have established VPC peering.
- Disconnected: If VPC peering is deleted at one side, the status at the other side is set to "disconnected".
Notification
If VPC peering has been established on both sides, a route policy needs to be configured on both sides for the resources to communicate with each other.
Billing model
Peering in the same region: Free.
Use constraint
Attentions regarding peering:
- To enable true communication between the two terminals of peering, it is necessary to ensure that the relevant routing rules are configured on the relevant route tables at both the local and opposite terminals.
- Currently, only the creation of VPC peering between VPCs in the same region and the use of VPC peering across accounts in the same region are supported.
- The interoperability achieved by VPCs via VPC peering will not transfer.
- Private network CIDRs at both terminals of peering cannot overlap; otherwise, an error will be reported;
- Peering can be disconnected at any time by either side. Traffic between the two private networks is disconnected immediately after disconnection.
- There is no bandwidth cap for peering in the same region.
Related References
-Overview of Route Table Features