D-Link DI-1750 Reference Manual page 231

It costs less because it does not require a fully meshed topology.
It is more reliable because it maintains connectivity in the event of VC failure.
To configure your OSPF network type, use the following command in interface configuration mode:
ip ospf
non-broadcast
[non-broadcast] }}
In the prompt Select 18 option ，It will list all arguments：
(00)access-group
......
(10)ospf
......
Please Input the code of command to be excute(0-18): 10
input 10，Select ospf option ，prompt is as below:
(00)cost
......
(05)network
......
Please Input the code of command to be excute(0-10): 5
input 5，Select network option ，prompt is as below:
(00)broadcast
(01)non-broadcast
(02)point-to-multipoint
(03)point-to-point
Please Input the code of command to be excute(0-3):
Select network type .
See the end of this chapter for an example of an OSPF point-to-multipoint network.
6.11.7 Configuring Point-to-Multipoint, Broadcast Networks
On point-to-multipoint, broadcast networks, there is no need to specify neighbors. However, you can
specify neighbors with the neighbor router configuration command, in which case you should specify a
cost to that neighbor.
Before the point-to-multipoint keyword was added to the ip ospf network interface configuration
command, some OSPF point-to-multipoint protocol traffic was treated as multicast traffic. Therefore,
the neighbor router configuration command was not needed for point-to-multipoint interfaces because
multicast took care of the traffic. Hello, update, and acknowledgment messages were sent using
multicast. In particular, multicast hello messages discovered all neighbors dynamically.
On any point-to-multipoint interface (broadcast or not), the router assumed that the cost to each
neighbor was equal. The cost was configured with the ip ospf cost interface confutation command. In
reality, the bandwidth to each neighbor is different, so the cost should differ. With this feature, you can
configure a separate cost to each neighbor. This feature applies to point-to-multipoint interfaces only.
To treat an interface as point-to-multipoint broadcast and assign a cost to each neighbor, use the
following commands beginning in interface configuration mode:
ip
point-to-multipoint
exit
router ospf process-id
Command
{broadcast
network
| {point-to-multipoint
Specify access control for packets
set OSPF parameter for this port
Interface cost
Network type
Set to broadcast
Set to non-broadcast
Set to point-to-multipoint
Set to point-to-point
Command
ospf network
Model Name
| Configures the OSPF network type for a specified
interface.
Function
Configure an interface
broadcast media.
Enter global configuration mode.
Configure an OSPF routing process and enter router
configuration mode.
- 229 -
Function
as point-to-multipoint for