Use the following best practices to help build your network topology:
- Enable graceful restart on your on-premises BGP device. With graceful restart, traffic between networks won't be disrupted in the event of a Cloud Router or BGP device failure as long as the BGP session is re-established within the graceful restart period.
- If graceful restart is not supported or enabled on your device, you should configure two on-premises devices with one tunnel each to provide redundancy. If you don't, Cloud VPN tunnel traffic can be disrupted in the event of Cloud Router or on-premises BGP device failure.
- For high reliability, set up redundant routers and BGP sessions even if your on-premises device supports graceful restart. In the event of non-transient failures, you are protected even if one path fails. For more information, see Redundant Cloud VPN tunnels.
- To connect your on-premises network to multiple Google Cloud projects by using dynamic routing, see these scenarios for VPC Network Peering or Shared VPC.
- To ensure that you do not exceed Cloud Router limits, create alerting policies by using Cloud Monitoring. For example, you can create alerting policies for the limits for learned routes by using the metrics for learned routes.