Installing and Administering Internet Services

Chapter 8 261
Configuring gated
Configuring the OSPF Protocol
Figure 8-4 Area Border Router Configuration Example
The following is an example of the area definitions in the router’s
/etc/gated.conf file:
ospf yes {
area 0.0.0.1 {
interface 193.2.1.33 {
...
} ;
} ;
area 0.0.0.2 {
interface 193.2.1.17 {
...
} ;
} ;
} ;
There are various other characteristics that you can define for the area
and for the interface(s). The following sections describe the configuration
statements that you use in defining an area.
Networks
The networks statement defines the address ranges that make up an
OSPF area. This definition applies only to area border routers, where
multiple areas are specified, and is required only if you need to compress
a number of subnets using a network mask.
Inside the networks statement, each IP address range is specified by a
network address followed by a hexadecimal bit mask. For example, the
following address range begins with the network address 193.2.1.16 and
includes the first 15 addresses in that network (193.2.1.17 through
193.2.1.31):
193.2.1.16 mask 0xfffffff0
Many separate networks can be specified in an address range. Area
border routers advertise a single route for each address range.
Area
Border
Router
193.2.1.17
193.2.1.33
to Network Bto Network A
Area 0.0.0.1
Area 0.0.0.2