Announcing Aggregate:Cisco IOS
network 101.10.0.0 mask 255.255.224.0
neighbor 102.102.10.1 remote-as 101
neighbor 102.102.10.1 prefix-list out-filter out
ip route 101.10.0.0 255.255.224.0 null0
ip prefix-list out-filter permit 101.10.0.0/19
ip prefix-list out-filter deny 0.0.0.0/0 le 32