Which two methods advertise internal networks to external ISPs via BGP? (Choose two.)

A.
using aggregate routes

B.
disabling synchronization

C.
forcing the next-hop address

D.
defining routes via the network statement

Explanation:
In BGP, the network command tells the BGP process what locally learned networks to advertise. The networks
can be connected routes, or routes learned by way of a dynamic routing protocol, such as RIP. These networks
must also exist in the routing table of the local router or they will not be sent out in updates. The mask keyword
can be used with the network command to specify individual subnets. Routes learned by the BGP process are
propagated be default but are often filtered by a routing policy.
Router(config-router)#network network-number (mask network-mask)