Cisco Systems 78-11741-02 Wireless Office Headset User Manual


 
Configuring OSPF
Configuring OSPF over Different Physical Networks
IPC-227
Cisco IOS IP Configuration Guide
To configure your OSPF network type, use the following command in interface configuration mode:
See the “OSPF Point-to-Multipoint Example” section at the end of this chapter for an example of an
OSPF point-to-multipoint network.
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 Cisco IOS software 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:
Repeat Step 4 for each neighbor if you want to specify a cost. Otherwise, neighbors will assume the cost
of the interface, based on the ip ospf cost interface configuration command.
Configuring OSPF for Nonbroadcast Networks
Because many routers might be attached to an OSPF network, a designated router is selected for the
network. Special configuration parameters are needed in the designated router selection if broadcast
capability is not configured.
Command Purpose
Router(config-if)# ip ospf network {broadcast |
non-broadcast | {point-to-multipoint
[non-broadcast] | point-to-point}}
Configures the OSPF network type for a specified interface.
Command Purpose
Step 1
Router(config-if)# ip ospf network
point-to-multipoint
Configures an interface as point-to-multipoint for
broadcast media.
Step 2
Router(config-if)# exit
Enters global configuration mode.
Step 3
Router(config)# router ospf process-id
Configures an OSPF routing process and enters router
configuration mode.
Step 4
Router(config-router)# neighbor ip-address cost
number
Specifies a neighbor and assigns a cost to the
neighbor.