What type of ASN do all BGP sessions with a Cloud Router require?

All BGP sessions with a Cloud Router require a private ASN (Autonomous System Number). A private ASN is designed for use within private networks and is specified for Border Gateway Protocol (BGP) configurations that do not need to be globally unique. In a Google Cloud environment, private ASNs allow organizations to set up BGP configurations for internal routing purposes without the need for a globally recognized ASN.

Using a private ASN is particularly beneficial in cloud architectures where resources might be scaled up or down, or when integrating with multiple networks. In contrast, public ASNs are needed when connecting to the public Internet, which is not the case for private BGP sessions within a Cloud Router.

Dynamic and static ASNs pertain to different configurations and uniqueness attributes, but they do not pertain to the specific requirements of BGP sessions with a Cloud Router in Google Cloud. Therefore, the choice of a private ASN aligns with the design and operational standards expected for interconnecting virtual private networks in cloud infrastructure.