What is the purpose of the BGP 'network' command with a network-number and mask?

• A. It tells BGP which networks to originate from the router into BGP
• B. It defines an interface
• C. It sets a static route
• D. It filters routes

Answer: (A)

In BGP, the network command with a network-number and mask is used to decide which local prefixes the router will originate into BGP. The network-number and mask specify the exact prefix you want to advertise. BGP will only originate that prefix if a matching route exists in the router’s local routing table (the RIB). If such a route is present, the router announces that prefix to its BGP peers; if not, nothing is advertised. This behavior distinguishes the network command from simply defining interfaces, setting static routes, or performing filtering, since those actions are separate, while the network statement specifically designates which local networks to originate into BGP.