Two routers become adjacent if at least one of them is Designated Router or Backup Designated Router ( on multiaccess type networks ), or they are interconnected by a point-to-point or point-to-multipoint network type.
2.
Two routers become adjacent if at least one of them is Designated Router or Backup Designated Router ( on multiaccess type networks ), or they are interconnected by a point-to-point or point-to-multipoint network type.