Border Gateway Protocol (BGP) is an inter-autonomous system routing protocol. An autonomous system (AS) is a network or group of routers logically organized and controlled by a common network administration. BGP enables routers to exchange network reachability information, including information about other ASs that traffic must traverse to reach other routers in other ASs. To implement BGP, the ASN must be specified in the config>router context. A 7210 SAS BGP configuration must contain at least one group and include information about at least one 7210 SAS neighbor (peer).
AS paths are the routes to each destination. Other attributes, such as the origin of the path, the multiple exit discriminator (MED), the local preference, and communities included with the route are called path attributes. When BGP interprets routing and topology information, loops can be detected and eliminated. Route preference for routes learned from the configured peers can be enabled among groups of routes to enforce administrative preferences and routing policy decisions.
MP-BGP (family IPv4 and IPv6) for use in Layer 3 VPN services (also known as VPRN services) is supported on all 7210 SAS platforms as described in this document.
BGP (family IPv4 and IPv6) is not available for use in the base routing instance. It is only available for use as a PE-CE routing protocol.
The L2-VPN (BGP-AD) and EVPN BGP address families are supported on all 7210 SAS platforms as described in this document.