The states of BGP neighbors are Idle/Conect/Active/OpenSent/OpenConfirm/Established. This section describes the states of these BGP neighbors.

bgp fast-external-fallover is a feature that immediately drops the neighbor if the interface used for the BGP connection goes down.

If a large amount of route information (prefix) is sent due to a neighbor’s misconfiguration, for example, the load on the router may increase and have an adverse effect on the router. Therefore, the neighbor maximum-prefix command is used to limit the number of route information received from BGP neighbors.

BGP neighbor authentication allows you to establish a neighbor only with a legitimate BGP router.
This section describes the configuration commands for neighbor authentication and a simple configuration example.

local-as allows you to establish a BGP neighbor for a specific EBGP neighbor with an AS other than the original AS number and exchange routes.
This section describes the operation of BGP local-as and the configuration commands.

There are various path attributes added to the BGP route. Well Known Mandatory attributes are always added to a BGP route.