Why it is suggest using network+slient issue routing in OSPF, not import direct routing.
1. Import direct will create OSPF external routing, which priority is less than OSPF internal routing.Using network+silent will create OSPF internal routing.
2. It's difficult to aggregate routing based on OSPF area if import direct routing, except NSSA area, but OSPF internal routing can be easily aggregated by ABR.
3. Importing direct routing will easily cause traffic abnormal when IP or mask is incorrectly configured.
For example, when configure GE1/0/0 IP 10.0.0.1/8, it may cause all the traffic visiting 10 IP segment be forwarded to this port. But network command need manually configured after that the routing can be issued.