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ADVANCED ROUTING (TGW & DX)

Advanced Routing: TGW & Direct Connect

Visualization: 1. VPC Peering (The Spaghetti Problem)
DOWNLOADING CONCEPT: 1. VPC PEERING (THE SPAGHETTI PROBLEM)...
  • ↳If you have two VPCs (e.g., Prod and Dev), they are completely isolated by default.
  • ↳To allow them to communicate over the private AWS backbone, you create a VPC Peering Connection.
  • ↳The catch? VPC Peering is Non-Transitive.
  • ↳If VPC A is peered with VPC B, and VPC A is peered with VPC C...
  • ↳VPC B *cannot* talk to VPC C! Traffic cannot route through a middleman.
  • ↳You must explicitly create a peering connection between B and C.
  • ↳If an enterprise has 100 VPCs, creating a full-mesh peering network requires 4,950 peering connections.
  • ↳It becomes an unmanageable spaghetti nightmare.
▲ LIVE INCIDENTYou successfully peered VPC-A (10.0.0.0/16) and VPC-B (10.0.0.0/16). The peering connection says 'Active', but instances in VPC-A cannot ping instances in VPC-B.
sre@arena:~/cloud-tgw
sre@arena:~$ aws ec2 create-vpc-peering-connection --vpc-id vpc-A --peer-vpc-id vpc-B