Configuring On-premises Routers

After you create a VLAN attachment, configure your on-premises router to establish a BGP session with your Cloud Router. Use the VLAN ID, interface IP address, and peering IP address provided by the VLAN attachment to configure your on-premises router.

On your on-premises router, configure the following settings:

  • MTU of 1440 on the IP subinterface
  • EBGP multi-hop for the BGP session
  • Use the default values for all timers such as the BGP session hold time.
  • If your device supports BGP graceful restart, enable it and use the recommended values for the restart and stalepath timers. Graceful restart prevents BGP sessions from dropping and routes from withdrawing during Cloud Router maintenance.

The following sections provide sample router configurations for different hardware. See the Vendor-specific notes section in the VPN Interop Guide for values for some platforms, or consult your on-premises device documentation for definite values.

After you configure your on-premises router, you can check the status of your BGP sessions by viewing the Cloud Router details.

Cisco

The sample configuration is for an interface on a Cisco ASR 1009 router that's running IOS-XE. Values for the following fields are provided by the VLAN attachment and Cloud Router.

For the BGP session:

  • remote-as — The AS number of your Cloud Router (65200).
  • neighbor IP address — The link local IP address of your Cloud Router's interface, from the cloudRouterIpAddress field (169.254.180.81).
  • graceful restart timer — 1 second.
  • stalepath timer — 300 seconds.

For Port-channel122.100:

  • encapsulation dot1Q — For Dedicated Interconnect, the VLAN ID allocated by the VLAN attachment (1000). For Partner Interconnect, the VLAN ID allocated by your service provider.
  • ip address — The on-premises router IP address, from the customerRouterIpAddress field (169.254.180.82).

Juniper

The sample configuration is for an interface on a Juniper MX-240 router. Values for the following fields are provided by the VLAN attachment and Cloud Router:

  • vlan-id — For Dedicated Interconnect, the VLAN ID allocated by the VLAN attachment (1000). For Partner Interconnect, the VLAN ID allocated by your service provider.
  • local-address — The on-premises router IP address (customerRouterIpAddress).
  • neighbor — The link local IP address of your Cloud Router's interface (cloudRouterIpAddress).
  • peer-as — The ASN of your Cloud Router.
  • graceful restart timer — 1 second.
  • stalepath timer — 300 seconds.

What's next

Check that your BGP sessions are working between your on-premises network and your Google VPC network. For more information, see Viewing Router Status and Advertised Routes in the Cloud Router documentation.
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