Question

Your company runs two custom-mode VPCs, prod-vpc and hybrid-vpc, connected via VPC Network Peering. hybrid-vpc has a Cloud Router and HA VPN tunnels to your on-premises data center, and Cloud Router learns on-premises prefixes via BGP as dynamic routes. Instances in prod-vpc need to reach on-premises hosts, but after establishing the peering they still cannot connect, even though instances in hybrid-vpc reach on-premises successfully. What must you do so prod-vpc can use the on-premises routes?

Accepted Answer

Enable exchange of custom routes (export) on the hybrid-vpc side of the peering and import of custom routes on the prod-vpc side.

Answer

Create a Cloud Router in prod-vpc and configure it to peer with the same on-premises BGP router.

Answer

Add static routes in prod-vpc pointing to the HA VPN gateway in hybrid-vpc as the next hop.

Answer

Delete and recreate the peering with transitive routing enabled so learned routes propagate automatically.