By default, how often does a router running IGRP send its complete routing table to its neighbors?（）

A. Point-to-point and point-to-multipoint networks
B. Nonbroadcast and broadcast multipoint multicasting
C. Point-to-point and multi-access broadcasting
D. Point-to-multipoint and multi-access broadcasting
E. Nonbroadcast and broadcast multi-access

A. Hierarchical OSPF networks need to be in one area
B. Multiple OSPF areas must connect to area 0
C. Single area OSPF networks must be configured in area 1
D. Areas can be assigned any number from 0 to 63535
E. Area 0 is called the backbone area
F. Each OSPF area need to be configured with a loopback interface

A. It confines network instability to a single area of network.
B. It increases the routing overhead of the network
C. It supports VLSM
D. It routes between Autonomous Systems.
E. It allows extensive control of routing updates
F. None of the above