ate routes. (Different routing protocols use different terms for groups of routes, be they subnets or major networks-BGP uses the term "aggregate," while OSPF uses the term "summary.") The destination for both summary routes is Nullo. Nullo as a destination indicates that packets sent to this network will be dropped. The summary routes point to Nullo because they were created within EIGRP on this router. The Nullo route is there for the routing protocol's use. The more specific routes must also be included in the routing table because the local router must use them when forwarding packets. The specific routes will not be advertised in the routing proto- col-only the summary will be advertised. We can see this if we look at an attached router: 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks 172.16.200.0/23 [90/156160] via 11.0.0.2, 04:30:21, FastEtherneto/1 172.16.202.0/24 [90/156160] via 11.0.0.2, 04:30:21, FastEtherneto/1 172.16.100.0/23 [90/156160] via 11.0.0.2, 04:30:21, FastEthernet0/1 172.16.101.0/24 is directly connected, Serialo/o On the connected router, the summary route for 172.16.200.0/23 is present, but the more specific routes 172.16.200.0/24 and 172.16.201.0/24 are not. Major Network A major network is a network that is in its native form. For example, the 10.0.0.0/8 network has a native subnet mask of 255.0.0.0. The network 10.0.0.0/8 is therefore a major network. Referencing 10.0.0.0 with a prefix mask longer than /8 changes the route to a subnet, while referencing it with a mask shorter than /8 changes the route to a supernet. Two major networks are shown in the routing table: 172.16.0.0/16 is variably subnetted, 6 subnets, 2 masks 172.16.200.0/23 is a summary, 00:56:18, Nullo 172.16.200.0/24 is directly connected, Loopback2 172.16.201.0/24 is directly connected, Serialo/o 172.16.202.0/24 is directly connected, Loopback3 172.16.100.0/23 is directly connected, Loopback4 172.16.101.0/24 [90/2172416] via 11.0.0.1, 00:53:07, FastEtherneto/1 10.0.0.0/8 is directly connected, FastEtherneto/o 11