Overview
Definition: A networking connection between two VPCs (in Cloud only, not on-prem VPCs) allowing traffic routing using private IPv4 or IPv6 addresses. Communication: Instances in either VPC can communicate as if within the same network. Types of VPC Peering Connections
Intra-Account: Between your own VPCs. Inter-Account: With a VPC in another AWS account. Inter-Region: Between VPCs in different regions. Inter-Region VPC Peering
Encryption: Data sent between VPCs in different regions is encrypted (traffic charges apply). Cannot create a security group rule referencing a peer security group. Cannot enable DNS resolution. Maximum MTU is 1500 bytes (no jumbo frames). Characteristics and Capabilities
Infrastructure: Uses existing VPC infrastructure (not a gateway or VPN, no separate physical hardware). Reliability: No single point of failure or bandwidth bottleneck. One-to-One Relationship: Only one peering connection between any two VPCs at a time. No Overlapping CIDR: CIDR ranges of the peered VPCs must not overlap. Multiple Connections: Can create multiple peering connections for each VPC, but transitive peering is not supported. Non-Transitive: No peering relationship with VPCs that are not directly peered. Limits: 50 VPC peers per VPC (up to 125 by request). DNS and Routing
DNS Support: Supported for VPC peering. Route Tables: Must update route tables to configure routing through the peering connection. Security Groups: Update inbound and outbound rules to reference security groups in the peered VPC. Creating VPC Peering Connections
Requires account ID and VPC ID from the other account. Must accept the pending access request in the peered VPC. Route Table Target: VPC peering connection appears as a target starting with "pcx-".
VPC Peering
