With custom route advertisements, you choose which routes Cloud Router advertises to your on-premises router through the Border Gateway Protocol (BGP).
You can specify route advertisements on the Cloud Router or on each BGP session. If you specify advertised routes on the Cloud Router, they apply to all BGP sessions on the Cloud Router. If you specify route advertisements on a BGP session, those advertisements replace the Cloud Router advertisements.
For more information about route advertisements and the default behavior, see Route advertisements in the Overview.
To create resources with custom route advertisements, see the following information:
To update existing resources with custom route advertisements, see the following information: