User's Manual

442
Users Manual of CS-6306R
45.3.3.3 Configuring OSPF in Different Physical Networks
OSPF divides the physical media of the network into the following classes:
 Broadcast network (Ethernet, Token Ring, FDDI)
 Non-broadcast and multi-access network (SMDS, Frame Relay, X.25)
 Point-to-point network (HDLC, PPP)
The X.25 and frame-relay network provides optional broadcast capability. You can configure the OSPF to run
in the broadcast network through the map command. For details of the map command, refer to the description
of the map command in WAN Command Reference.
45.3.3.4 Configuring OSPF Network Type
No matter what physical media type your network belongs to, you can configure your network to be the
broadcast network or the non-broadcast and multi-access network. This feature allows you configure the
network flexibly. You can configure the broadcast network to the non-broadcast and multi-access network;
you also can configure the non-broadcast network, such as X.25, Frame Relay and SMDS, to the broadcast
network. The feature also eases the neighbor’s configuration. For details, refer to contents about OSPF
configuration of non-broadcast network.
Configuring the non-broadcast and multi-access network to a broadcast network or a non-broadcast network
is to suppose that the virtual link exists between two random switches or to suppose that the network is a
mesh network. The previous configuration is unreal because it costs too much. You may configure the
non-broadcast and multi-access network to a partly meshed network. To save the expense, you can configure
the non-broadcast and multi-access network to a point-to-multipoint network. The disconnected switches can
exchange the routing information with each other through the virtual link.
The interface connecting the OSPF point to other points is defined as the point-to-multipoint network interface.
It creates lots of host routes. Comparing with the non-broadcast and multi-access network or the
point-to-point network, the OSPF point-to-multipoint network has the following advantages:
 The point-to-multipoint network is easy to configure. The configuration does not need the neighbor
configuration commands. It only needs an IP address and there is no DR.
 The point-to-multipoint network does not need the wholly meshed network's topology, so the expense is
smaller.
 It is more reliable. The connection can keep working even if the virtual link fails.
Run the following commands in interface configuration mode to configure the type of the OSPF network.
Command Purpose
ip ospf network {broadcast |
non-broadcast | {point-to-multipoint
[non-broadcast] }}
Configures the network type of the
OSPF.
The network of the switch is a broadcast network.