Border Gateway Protocol (BGP), a dynamic routing protocol based on TCP protocol, is designed to exchange routing and reachability information among autonomous systems (AS). During the construction of leased line access, you can use BGP to achieve intranet connection between an on-premises IDC and a VBR. BGP can help you build a hybrid cloud in a more efficient, flexible, and reliable way.
BGP groups are used for simplifying BGP configurations. Adding repeated configurations into a BGP group can reduce configuration complexity. You only need to create a BGP group based on the ASN and add BGP peers meeting requirements into the group. Then BGP peers in the BGP group will inherit the configurations of the BGP group, and you do not need to configure the BGP peers separately.
Note the following when using BGP:
VBR only supports building BGP peers with a peer on-premises IDC, and still need to use static routing to communication with a VPC.
The supported BGP version is BGP4.
VBR supports IPv4 GBP, but does not support IPv6 BGP.
Up to eight BGP peers can be created under each VBR.
Up to 100 dynamic route entries can be added to a BGP peer.
The Alibaba Cloud-side ASN is 45104. The customer side can transmit 2-byte or 4-byte ASN.